PM620, PM622, PM820, PM822 and PM825 Cold Planers Electronic System Sensor Signal (PWM)

Table 1
Machine ECM (MID 39)
DTC	Code Description	System Response
3880-3	Left Rear Leg Cylinder Position Sensor : Voltage Above Normal	A Level 2 warning will activate. All legs raise and lower closed loop functionality will remain functional if fault is active.
3880-4	Left Rear Leg Cylinder Position Sensor : Voltage Below Normal	A Level 2 warning will activate. All legs raise and lower closed loop functionality will remain functional if fault is active.
3880-8	Left Rear Leg Cylinder Position Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. All legs raise and lower closed loop functionality will remain functional if fault is active.
3881-3	Left Front Leg Cylinder Position Sensor : Voltage Above Normal	A Level 2 warning will activate. All legs raise and lower closed loop functionality will remain functional if fault is active.
3881-4	Left Front Leg Cylinder Position Sensor : Voltage Below Normal	A Level 2 warning will activate. All legs raise and lower closed loop functionality will remain functional if fault is active.
3881-8	Left Front Leg Cylinder Position Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. All legs raise and lower closed loop functionality will remain functional if fault is active.
3882-3	Right Rear Leg Cylinder Position Sensor : Voltage Above Normal	A Level 2 warning will activate. All legs raise and lower closed loop functionality will remain functional if fault is active.
3882-4	Right Rear Leg Cylinder Position Sensor : Voltage Below Normal	A Level 2 warning will activate. All legs raise and lower closed loop functionality will remain functional if fault is active.
3882-8	Right Rear Leg Cylinder Position Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. All legs raise and lower closed loop functionality will remain functional if fault is active.
3883-3	Right Front Leg Cylinder Position Sensor : Voltage Above Normal	A Level 2 warning will activate. All legs raise and lower closed loop functionality will remain functional if fault is active.
3883-4	Right Front Leg Cylinder Position Sensor : Voltage Below Normal	A Level 2 warning will activate. All legs raise and lower closed loop functionality will remain functional if fault is active.
3883-8	Right Front Leg Cylinder Position Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. All legs raise and lower closed loop functionality will remain functional if fault is active.

Pulse Width Modulation (PWM) is a technique for controlling analog circuits with digital outputs. PWM is employed in various applications ranging from measurement to communication with the Electronic Control Module (ECM). The duty cycle of a square wave is modulated to encode a specific analog signal level. The duty cycle is the ratio of the on-time to the period. The modulating frequency is the inverse of the period. The duty cycle is programmed into the software of the ECM. The engineer (or programmer) sets the period in the on-chip timer counter that provides the modulating square wave. The engineer sets the direction of the PWM output along with the on-time in the PWM control register.

One of the advantages of the PWM sensor is that the signal is digital from the ECM to the controlled system. No digital to analog conversion is necessary. By using a digital signal, noise effects are minimized. Noise affects a digital signal if the noise can change a logic 1 to a logic 0 or a logic 0 to a logic 1.

Possible causes for an FMI 3 Diagnostic Code are:

The sensor has failed.
The sensor supply or the ground circuit in the machine harness is open.
The signal circuit in the machine harness is shorted to the +battery.
The signal circuit in the machine harness is open or the sensor is disconnected.
The ECM has failed. A failure of the ECM is unlikely.

Possible causes for an FMI 4 Diagnostic Code are:

The sensor has failed.
The signal circuit in the machine harness is shorted to ground.
The ECM has failed. A failure of the ECM is unlikely.

Possible causes for an FMI 8 Diagnostic Code are:

The sensor has failed.
The wrong sensor is installed.
Intermittent connections or poor connections.
The ECM has failed. A failure of the ECM is unlikely.

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Illustration 1	g06014170
Sensor Signal (PWM) Electrical Connections for the Machine ECM

Note: The diagram above is a simplified schematic of the Machine ECM. The schematic is electrically correct. However, not all the possible harness connectors are shown.Refer to the appropriate media number below for the complete Electrical Schematic: (S/N: JCF; LH9; 8RF; EL6) Machines refer to Electrical Schematic, UENR6397. (S/N: JB9; JFC; LB8; FG4; TPH; XS6) Machines refer to Electrical Schematic, UENR6398. (S/N: JB7; HN8; HC8; RL3; H6S; 626) Machines refer to Electrical Schematic, UENR8363. (S/N: SL8; TLZ; ESE; AK5; AN8; EE2; E8S; 3C6; 627) Machines refer to Electrical Schematic, UENR8362.The schematic will illustrate locations for all the electrical components and harness connectors that are installed on the machine.

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Table 2
Left and Right, Front and Rear Cylinder Position Sensors DTC 3880, 3881, 3882, 3883 Cylinder Stroke 710 mm (27.95 inch) Frequency: 250 ±15 Hz
PWM %	Cylinder Position
5%	Fully Retracted
95%	Fully Extended

The table above is a reference that can be used when checking the signal of the PWM sensors.

Diagnostic Trouble Code Procedure

Note: Prior to beginning this procedure, use Cat^® Electronic Technician (Cat ET) or the machine monitor to check for an active DTC 41 code. The DTC 41 indicates a failure of the 8 VDC power supply on the ECM. If the code is present, refer to the Sensor Supply - Test story to correct this problem before continuing. For transducers powered via the fuse panel, check the condition of the appropriate fuse before beginning the troubleshooting procedure.

Note: Prior to beginning this procedure, inspect the harness connectors involved in this circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, secure, and in good condition. If a problem with a connection is found, correct the problem. Verify that the diagnostic code is active before performing a troubleshooting procedure. For sensors powered via the fuse panel, check the condition of the appropriate fuse before beginning the troubleshooting procedure.

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Table 3
Troubleshooting Test Steps	Values	Results
1. Identify Active FMI Code Associated With Sensor Circuit	Code present	FMI 3 diagnostic code, proceed to Test Step 2. FMI 4 diagnostic code, proceed to Test Step 6. FMI 8 diagnostic code, proceed to Test Step 8.
Begin Process For FMI 3 Troubleshooting HERE
2. Check The Control And The Harness A. Turn the key start switch and disconnect switch to the ON position. B. Disconnect the machine harness from the sensor. C. Refer to the schematic to determine the voltage source for the suspected faulty sensor. D. Measure voltage between signal and ground contacts at the machine harness connector for the sensor.	Voltage is 8.0 VDC ± 0.5 VDC or 24.0 VDC ± 1.0.	OK - The voltage reading is correct for the suspected faulty sensor. Proceed to Test Step 3. NOT OK- The voltage is NOT correct for the circuit. Repair - Refer to the diagnostic code procedure in this manual for troubleshooting of the power supply. After the power supply procedure is performed, verify the status of the sensor diagnostic code before proceeding. Proceed to Test Step 3.
3. Check For An Open In The Sensor Circuit A. The sensor remains disconnected from the machine harness. B. Turn the key start switch and the disconnect switch to the OFF position. C. At the harness connector for the sensor, place a jumper wire between Pin 2 (or Pin B) and Pin 3 (or Pin C). These locations are also referred to as the ground contact and the signal contact. D. Disconnect harness connectors from the ECM. E. At machine harness connector for sensor, measure the resistance from the signal contact to return contact. F. Gently pull on the wires and move the wires in a circular motion at ECM connector and observe the resistance readings. Repeat the process for the sensor connector.	The resistance is less than 5 Ω at all times during the manipulation of the harness.	OK - The resistance is less than 5 Ω. The signal circuit and the ground circuits of the sensor are not open in the machine harness. Proceed to Test Step 4. NOT OK - Resistance reading for the signal circuit or the return circuit is greater than 5 Ω. Repair: Check the signal circuit or the ground circuit for opens or bad connections. Repair or replace the machine harness, if necessary. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or a corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
4. Check Signal Circuit For A Short To +Battery A. The Sensor and the ECM are disconnected from the harness. B. Turn the disconnect switch and the key start switch to the OFF position. C. Measure the resistance between the signal and +battery contacts of the harness connector for the sensor. D. At machine harness connector, measure the resistance from signal contact to all possible sources of +battery.	Resistance is greater than 5K Ω for all readings.	OK - The resistance is greater than 5K Ω. The harness circuit is correct. Proceed to Test Step 5. NOT OK - The resistance less than 5 Ω. Repair: A short exists in the harness between the +battery and signal circuit. Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
5. Check The Harness For An Open A. The disconnect switch and key start switch are in the OFF position. B. The sensor and ECM are disconnected from the harness. C. Connect a jumper wire from the end of the signal wire at the ECM to a known ground. D. Measure the resistance of the signal wire at the ECM.	Resistance is less than 5 Ω.	OK - The resistance of the signal wire is less than 5 Ω. Proceed to Test Step 14. NOT OK - The resistance is greater than 5K Ω. The signal wire is open in the machine harness. Repair: Repair or replace the harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
Begin Process For FMI 4 Troubleshooting HERE
6. Check The Sensor A. With the FMI 4 diagnostic code active, disconnect the sensor from the machine harness. B. Observe Cat^® Electronic Technician (Cat ^®ET) or the operator monitor for code change as the sensor is disconnected and connected to the harness.	Code changes from FMI 4 to FMI 3.	OK - The FMI 4 diagnostic code remains active when sensor is disconnected. The sensor is not the cause of the problem. Proceed to Test Step 7. NOT OK - The diagnostic changed to an FMI 3 when the sensor was disconnected. Repair: Replace the sensor. STOP
7. Check The Signal Circuit For A Short To Ground A. Turn the key start switch and the disconnect switch to the OFF position. B. Disconnect the harness connector from the ECM. C. Measure the resistance between the signal contact for sensor and frame ground.	The resistance is greater than 5K Ω.	OK - The resistance is greater than 5K Ω. The harness circuit is correct. Proceed to Test Step 14. NOT OK - The resistance is less than 5 Ω. A short circuit exists between frame ground and the signal circuit. Repair: Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
Begin Process For FMI 8 Troubleshooting HERE
8. Check Harness For An Open A. Turn the disconnect switch and the key start switch to the OFF position. B. The sensor and ECM are disconnected from the harness. C. Connect a jumper wire from the end of signal wire at the ECM to a known ground. D. Measure the resistance of the signal wire at the ECM.	The reading is less than 5 Ω.	OK - The measurement is less than 5 Ω. Proceed to Test Step 9. NOT OK - The measurement is greater than 5K Ω. The signal circuit in the harness is open. Repair: Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or a corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
9. Check The Signal Circuit For A Short To Ground A. Turn key start switch and disconnect switch to the OFF position. B. Disconnect the harness connector from the ECM (or "Switch Panel"). C. Measure the resistance between the signal contact for the sensor and frame ground.	Reading is greater than 5K Ω.	OK - Measurement is greater than 5K Ω. Proceed to Test Step 10. NOT OK - Measurement is less than 5 Ω. The signal circuit in the harness is shorted to ground. Repair: Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
10. Check The Sensor For A Short To Case A. Turn the key start switch and the disconnect switch to the OFF position. B. At the machine harness connector for the sensor, measure the resistance between each contact of the sensor (1, 2, 3, or A, B, C). Connect the ground lead of the meter to an unpainted location on case of sensor.	The reading is greater than 5K Ω.	OK - All measurements are greater than 5K Ω. Proceed to Test Step 11. NOT OK - A measurement is less than 5 Ω. The sensor has failed. Repair: Replace the sensor. Confirm that the new sensor corrects the problem. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
11. Check The Sensor A. Turn the key start switch and the disconnect switch to the ON position. B. Use Cat ^® ET (or the operator monitor) to confirm the existence of the diagnostic code. C. Disconnect the sensor from machine harness.	The diagnostic code is no longer present.	OK - Diagnostic code is NO longer active. The sensor has failed. Repair: Replace the sensor. Verify new sensor corrected the diagnostic code. STOP NOT OK - The diagnostic code remains active. Proceed to Test Step 12.
12. Check If The Diagnostic Code Remains A. Turn the key start switch and the disconnect switch to the ON position. B. Clear all diagnostic codes. C. Operate the machine. D. Stop machine and engage the safety lock lever. E. Check if the diagnostic code for the sensor is active.	The code for the sensor is NO longer present.	OK - The diagnostic code does not exist at this time. The initial diagnostic code may have been caused by a poor electrical connection or a short at one of the harness connections. Resume machine operation. STOP NOT OK - The diagnostic trouble code has not been corrected. Repair: Recheck the circuit and perform this procedure again. If the diagnostic code is still active, the Machine ECM may require replacement. Prior to replacing the ECM, always contact the Technical Communicator at your dealership for possible consultation with AVSpare. This consultation may effect repair time. If replacement is recommended, follow the procedure in Troubleshooting, "ECM - Replace". STOP

Transmission ECM

The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the PWM Sensors of the Transmission ECM.

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Table 4
Transmission ECM (MID 81)
DTC	Code Description	System Response
2976-3	Parking Brake Oil Pressure Sensor : Voltage Above Normal	A Level 1 warning will activate. The machine will be allowed to continue propelling without stopping.
2976-4	Parking Brake Oil Pressure Sensor : Voltage Below Normal	A Level 1 warning will activate. The machine will be allowed to continue propelling without stopping.
2976-8	Parking Brake Oil Pressure Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 1 warning will activate. The machine will be allowed to continue propelling without stopping.
3858-3	Drive Circuit #1 Pressure Sensor : Voltage Above Normal	A Level 2 warning will activate. The machine will be allowed to continue propelling without stopping. The propel system will go into an open loop mode, disabling the closed loop pressure balance, if the fault is active.
3858-4	Drive Circuit #1 Pressure Sensor : Voltage Below Normal	A Level 2 warning will activate. The machine will be allowed to continue propelling without stopping. The propel system will go into an open loop mode, disabling the closed loop pressure balance, if the fault is active.
3858-8	Drive Circuit #1 Pressure Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. The machine will be allowed to continue propelling without stopping. The propel system will go into an open loop mode, disabling the closed loop pressure balance, if the fault is active.
3858-13	Drive Circuit #1 Pressure Sensor : Out of Calibration	A Level 1 warning will activate.
3859-3	Drive Circuit #2 Pressure Sensor : Voltage Above Normal	A Level 2 warning will activate. The machine will be allowed to continue propelling without stopping. The propel system will go into an open loop mode, disabling the closed loop pressure balance, if the fault is active.
3859-4	Drive Circuit #2 Pressure Sensor : Voltage Below Normal	A Level 2 warning will activate. The machine will be allowed to continue propelling without stopping. The propel system will go into an open loop mode, disabling the closed loop pressure balance, if the fault is active.
3859-8	Drive Circuit #2 Pressure Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. The machine will be allowed to continue propelling without stopping. The propel system will go into an open loop mode, disabling the closed loop pressure balance, if the fault is active.
3859-13	Drive Circuit #2 Pressure Sensor : Out of Calibration	A Level 1 warning will activate.
3886-3	Right Side Plate Front Cylinder Position Sensor : Voltage Above Normal	A Level 2 warning will activate. If the fault is active, the right side plate control will go into an open loop mode where the front is not commanded to raise before the rear. Both front and rear will be commanded to raise (and lower) at the same time.
3886-4	Right Side Plate Front Cylinder Position Sensor : Voltage Below Normal	A Level 2 warning will activate. If the fault is active, the right side plate control will go into an open loop mode where the front is not commanded to raise before the rear. Both front and rear will be commanded to raise (and lower) at the same time.
3886-8	Right Side Plate Front Cylinder Position Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. If the fault is active, the right side plate control will go into an open loop mode where the front is not commanded to raise before the rear. Both front and rear will be commanded to raise (and lower) at the same time.
3887-3	Right Side Plate Rear Cylinder Position Sensor : Voltage Above Normal	A Level 2 warning will activate. If the fault is active, the right side plate control will go into an open loop mode where the front is not commanded to raise before the rear. Both front and rear will be commanded to raise (and lower) at the same time.
3887-4	Right Side Plate Rear Cylinder Position Sensor : Voltage Below Normal	A Level 2 warning will activate. If the fault is active, the right side plate control will go into an open loop mode where the front is not commanded to raise before the rear. Both front and rear will be commanded to raise (and lower) at the same time.
3887-8	Right Side Plate Rear Cylinder Position Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. If the fault is active, the right side plate control will go into an open loop mode where the front is not commanded to raise before the rear. Both front and rear will be commanded to raise (and lower) at the same time.

Possible causes for an FMI 3 Diagnostic Code are:

The sensor has failed.
The sensor supply or the ground circuit in the machine harness is open.
The signal circuit in the machine harness is shorted to the +battery.
The signal circuit in the machine harness is open or the sensor is disconnected.
The ECM has failed. A failure of the ECM is unlikely.

Possible causes for an FMI 4 Diagnostic Code are:

The sensor has failed.
The signal circuit in the machine harness is shorted to ground.
The ECM has failed. A failure of the ECM is unlikely.

Possible causes for an FMI 8 Diagnostic Code are:

The sensor has failed.
The wrong sensor is installed.
Intermittent connections or poor connections.
The ECM has failed. A failure of the ECM is unlikely.

Possible causes for an FMI 13 diagnostic code are:

The sensor is out of calibration.
The ECM has failed. A failure of the ECM is unlikely.

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Illustration 2	g06014229
Sensor Signal (PWM) Electrical Connections for the Transmission ECM

Note: The diagram above is a simplified schematic of the Transmission ECM. The schematic is electrically correct. However, not all the possible harness connectors are shown.Refer to the appropriate media number below for the complete Electrical Schematic: (S/N: JCF; LH9; 8RF; EL6) Machines refer to Electrical Schematic, UENR6397. (S/N: JB9; JFC; LB8; FG4; TPH; XS6) Machines refer to Electrical Schematic, UENR6398. (S/N: JB7; HN8; HC8; RL3; H6S; 626) Machines refer to Electrical Schematic, UENR8363. (S/N: SL8; TLZ; ESE; AK5; AN8; EE2; E8S; 3C6; 627) Machines refer to Electrical Schematic, UENR8362.The schematic will illustrate locations for all the electrical components and harness connectors that are installed on the machine.

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Table 5
Right Side Plate Front and Rear Cylinder Position Sensors DTC 3886, 3887 Cylinder Stroke 515 mm (20.28 inch) Frequency: 250 ±15 Hz
PWM %	Cylinder Position
5%	Fully Retracted
95%	Fully Extended

Brake, Drive Circuit #1 and #2 Pressure Sensors DTC 2976, 3858, 3859 Frequency: 500 ±100 Hz, 5 - 95 % PWM

The table above is a reference that can be used when checking the signal of the PWM sensors.

Diagnostic Trouble Code Procedure

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Table 6
Troubleshooting Test Steps	Values	Results
1. Identify Active FMI Code Associated With Sensor Circuit	Code present	FMI 3 diagnostic code, proceed to Test Step 2. FMI 4 diagnostic code, proceed to Test Step 6. FMI 8 diagnostic code, proceed to Test Step 8.
Begin Process For FMI 3 Troubleshooting HERE
2. Check The Control And The Harness A. Turn the key start switch and disconnect switch to the ON position. B. Disconnect the machine harness from the sensor. C. Refer to the schematic to determine the voltage source for the suspected faulty sensor. D. Measure voltage between signal and ground contacts at the machine harness connector for the sensor.	Voltage is 8.0 VDC ± 0.5 VDC or 24.0 VDC ± 1.0.	OK - The voltage reading is correct for the suspected faulty sensor. Proceed to Test Step 3. NOT OK- The voltage is NOT correct for the circuit. Repair - Refer to the diagnostic code procedure in this manual for troubleshooting of the power supply. After the power supply procedure is performed, verify the status of the sensor diagnostic code before proceeding. Proceed to Test Step 3.
3. Check For An Open In The Sensor Circuit A. The sensor remains disconnected from the machine harness. B. Turn the key start switch and the disconnect switch to the OFF position. C. At the harness connector for the sensor, place a jumper wire between Pin 2 (or Pin B) and Pin 3 (or Pin C). These locations are also referred to as the ground contact and the signal contact. D. Disconnect harness connectors from the ECM. E. At machine harness connector for sensor, measure the resistance from the signal contact to return contact. F. Gently pull on the wires and move the wires in a circular motion at ECM connector and observe the resistance readings. Repeat the process for the sensor connector.	The resistance is less than 5 Ω at all times during the manipulation of the harness.	OK - The resistance is less than 5 Ω. The signal circuit and the ground circuits of the sensor are not open in the machine harness. Proceed to Test Step 4. NOT OK - Resistance reading for the signal circuit or the return circuit is greater than 5 Ω. Repair: Check the signal circuit or the ground circuit for opens or bad connections. Repair or replace the machine harness, if necessary. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or a corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
4. Check Signal Circuit For A Short To +Battery A. The Sensor and the ECM are disconnected from the harness. B. Turn the disconnect switch and the key start switch to the OFF position. C. Measure the resistance between the signal and +battery contacts of the harness connector for the sensor. D. At machine harness connector, measure the resistance from signal contact to all possible sources of +battery.	Resistance is greater than 5K Ω for all readings.	OK - The resistance is greater than 5K Ω. The harness circuit is correct. Proceed to Test Step 5. NOT OK - The resistance less than 5 Ω. Repair: A short exists in the harness between the +battery and signal circuit. Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
5. Check The Harness For An Open A. The disconnect switch and key start switch are in the OFF position. B. The sensor and ECM are disconnected from the harness. C. Connect a jumper wire from the end of the signal wire at the ECM to a known ground. D. Measure the resistance of the signal wire at the ECM.	Resistance is less than 5 Ω.	OK - The resistance of the signal wire is less than 5 Ω. Proceed to Test Step 14. NOT OK - The resistance is greater than 5K Ω. The signal wire is open in the machine harness. Repair: Repair or replace the harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
Begin Process For FMI 4 Troubleshooting HERE
6. Check The Sensor A. With the FMI 4 diagnostic code active, disconnect the sensor from the machine harness. B. Observe Cat^® Electronic Technician (Cat ^®ET) or the operator monitor for code change as the sensor is disconnected and connected to the harness.	Code changes from FMI 4 to FMI 3.	OK - The FMI 4 diagnostic code remains active when sensor is disconnected. The sensor is not the cause of the problem. Proceed to Test Step 7. NOT OK - The diagnostic changed to an FMI 3 when the sensor was disconnected. Repair: Replace the sensor. STOP
7. Check The Signal Circuit For A Short To Ground A. Turn the key start switch and the disconnect switch to the OFF position. B. Disconnect the harness connector from the ECM. C. Measure the resistance between the signal contact for sensor and frame ground.	The resistance is greater than 5K Ω.	OK - The resistance is greater than 5K Ω. The harness circuit is correct. Proceed to Test Step 14. NOT OK - The resistance is less than 5 Ω. A short circuit exists between frame ground and the signal circuit. Repair: Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
Begin Process For FMI 8 Troubleshooting HERE
8. Check Harness For An Open A. Turn the disconnect switch and the key start switch to the OFF position. B. The sensor and ECM are disconnected from the harness. C. Connect a jumper wire from the end of signal wire at the ECM to a known ground. D. Measure the resistance of the signal wire at the ECM.	The reading is less than 5 Ω.	OK - The measurement is less than 5 Ω. Proceed to Test Step 9. NOT OK - The measurement is greater than 5K Ω. The signal circuit in the harness is open. Repair: Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or a corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
9. Check The Signal Circuit For A Short To Ground A. Turn key start switch and disconnect switch to the OFF position. B. Disconnect the harness connector from the ECM (or "Switch Panel"). C. Measure the resistance between the signal contact for the sensor and frame ground.	Reading is greater than 5K Ω.	OK - Measurement is greater than 5K Ω. Proceed to Test Step 10. NOT OK - Measurement is less than 5 Ω. The signal circuit in the harness is shorted to ground. Repair: Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
10. Check The Sensor For A Short To Case A. Turn the key start switch and the disconnect switch to the OFF position. B. At the machine harness connector for the sensor, measure the resistance between each contact of the sensor (1, 2, 3, or A, B, C). Connect the ground lead of the meter to an unpainted location on case of sensor.	The reading is greater than 5K Ω.	OK - All measurements are greater than 5K Ω. Proceed to Test Step 11. NOT OK - A measurement is less than 5 Ω. The sensor has failed. Repair: Replace the sensor. Confirm that the new sensor corrects the problem. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
11. Check The Sensor A. Turn the key start switch and the disconnect switch to the ON position. B. Use Cat ^® ET (or the operator monitor) to confirm the existence of the diagnostic code. C. Disconnect the sensor from machine harness.	The diagnostic code is no longer present.	OK - Diagnostic code is NO longer active. The sensor has failed. Repair: Replace the sensor. Verify new sensor corrected the diagnostic code. STOP NOT OK - The diagnostic code remains active. Proceed to Test Step 12.
12. Check If The Diagnostic Code Remains A. Turn the key start switch and the disconnect switch to the ON position. B. Clear all diagnostic codes. C. Operate the machine. D. Stop machine and engage the safety lock lever. E. Check if the diagnostic code for the sensor is active.	The code for the sensor is NO longer present.	OK - The diagnostic code does not exist at this time. The initial diagnostic code may have been caused by a poor electrical connection or a short at one of the harness connections. Resume machine operation. STOP NOT OK - The diagnostic trouble code has not been corrected. Repair: Recheck the circuit and perform this procedure again. If the diagnostic code is still active, the Machine ECM may require replacement. Prior to replacing the ECM, always contact the Technical Communicator at your dealership for possible consultation with AVSpare. This consultation may effect repair time. If replacement is recommended, follow the procedure in Troubleshooting, "ECM - Replace". STOP
Begin Process for FMI 13 Troubleshooting HERE
Troubleshooting Test Steps	Values	Results
1. Check the Calibration A. Perform the calibration procedure for the sensor. Refer to the UENR6292 , "Testing and Adjusting" , Propel Pump Pressure Override - Calibrate procedure. B. Observe the status of the diagnostic code.	The code is no longer active.	OK - The FMI 13 is no longer active. The calibration corrected the condition that caused the diagnostic code Proceed to Test Step 2. NOT OK -The FMI 13 Code is active. The diagnostic code has not been corrected. Verify that the correct software has been flashed into the ECM, or that the correct ECM is installed on the machine. Then repeat the calibration Proceed to Test Step 2.
2. Check If The Diagnostic Code Remains A. Reconnect all harness connectors. Check the sensor, sensor wiring, and pump main relief settings. The pump relief settings should measure between 40,000 kPa (5802 psi) and 46,000 kPa (6672 psi). B. Ensure that the key start switch and disconnect switch are ON. C. Clear all diagnostic codes. D. Operate the machine. E. Stop the machine and engage the Parking Brake. F. Check if the diagnostic code is active.	The diagnostic code is no longer present.	OK - The diagnostic code does not exist currently. The initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation. STOP. NOT OK - The diagnostic trouble code has not been corrected. If the diagnostic code has not been corrected after performing the procedure a second time, the ECM may require replacement. Prior to replacing the ECM, always contact the Technical Communicator at your dealership for possible consultation with AVSpare. This consultation may effect repair time. Follow the steps in Troubleshooting, "ECM - Replace" if the ECM needs to be replaced. STOP.

Steering ECM

The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the PWM Sensors of the Machine ECM.

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Table 7
Steering ECM (MID 150)
DTC	Code Description	System Response
3884-3	Left Side Plate Front Cylinder Position Sensor : Voltage Above Normal	A Level 2 warning will activate. If the fault is active, the left side plate control will go into an open loop mode where the front is not commanded to raise before the rear. Both front and rear will be commanded to raise (and lower) at the same time.
3884-4	Left Side Plate Front Cylinder Position Sensor : Voltage Below Normal	A Level 2 warning will activate. If the fault is active, the left side plate control will go into an open loop mode where the front is not commanded to raise before the rear. Both front and rear will be commanded to raise (and lower) at the same time.
3884-8	Left Side Plate Front Cylinder Position Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. If the fault is active, the left side plate control will go into an open loop mode where the front is not commanded to raise before the rear. Both front and rear will be commanded to raise (and lower) at the same time.
3885-3	Left Side Plate Rear Cylinder Position Sensor : Voltage Above Normal	A Level 2 warning will activate. If the fault is active, the left side plate control will go into an open loop mode where the front is not commanded to raise before the rear. Both front and rear will be commanded to raise (and lower) at the same time.
3885-4	Left Side Plate Rear Cylinder Position Sensor : Voltage Below Normal	A Level 2 warning will activate. If the fault is active, the left side plate control will go into an open loop mode where the front is not commanded to raise before the rear. Both front and rear will be commanded to raise (and lower) at the same time.
3885-8	Left Side Plate Rear Cylinder Position Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. If the fault is active, the left side plate control will go into an open loop mode where the front is not commanded to raise before the rear. Both front and rear will be commanded to raise (and lower) at the same time.
3888-3	Front Steering Cylinder Position Sensor : Voltage Above Normal	A Level 2 warning will activate. The steering mode shall be set to rear mode and will not be allowed to change if the fault is active. The front true track will be disabled and the front toe cylinder shall be fully extended to eliminate track binding.
3888-4	Front Steering Cylinder Position Sensor : Voltage Below Normal	A Level 2 warning will activate. The steering mode shall be set to rear mode and will not be allowed to change if the fault is active. The front true track will be disabled and the front toe cylinder shall be fully extended to eliminate track binding.
3888-8	Front Steering Cylinder Position Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. The steering mode shall be set to rear mode and will not be allowed to change if the fault is active. The front true track will be disabled and the front toe cylinder shall be fully extended to eliminate track binding.
3889-3	Front Toe Cylinder Position Sensor : Voltage Above Normal	A Level 2 warning will activate. The front true track will be disabled. The Front Toe Out Solenoid shall be commanded at full current if the fault is active to eliminate track binding.
3889-4	Front Toe Cylinder Position Sensor : Voltage Below Normal	A Level 2 warning will activate. The front true track will be disabled. The Front Toe Out Solenoid shall be commanded at full current if the fault is active to eliminate track binding.
3889-8	Front Toe Cylinder Position Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. The front true track will be disabled. The Front Toe Out Solenoid shall be commanded at full current if the fault is active to eliminate track binding.
3890-3	Rear Steering Cylinder Position Sensor : Voltage Above Normal	A Level 2 warning will activate. The steering mode shall be set to rear mode and will not be allowed to change if the fault is active. The rear true track will be disabled and the rear toe cylinder shall be fully extended to eliminate a potential over center condition.
3890-4	Rear Steering Cylinder Position Sensor : Voltage Below Normal	A Level 2 warning will activate. The steering mode shall be set to rear mode and will not be allowed to change if the fault is active. The rear true track will be disabled and the rear toe cylinder shall be fully extended to eliminate a potential over center condition..
3890-8	Rear Steering Cylinder Position Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. The front true track will be disabled. The Front Toe Out Solenoid shall be commanded at full current if the fault is active to eliminate track binding..
3891-3	Rear Toe Cylinder Position Sensor : Voltage Above Normal	A Level 1 warning will activate. The rear true track will be disabled. If there are no active faults on the Rear Steering Cylinder Position Sensor (3890-3, 3890-4 or 3890-8), the Rear Toe In Solenoid shall be commanded at full current to eliminate track binding and The Rear Steering Cylinder should not be allowed to retract below 39.9 mm if the fault is active. However, if there is an active fault on the Rear Steering Cylinder Position Sensor (3890-3, 3890-4 or 3890-8) the Rear Toe Out Solenoid shall be commanded at full current if the fault is active. This action will result in track binding, but is required to ensure an over center condition does not occur.
3891-4	Rear Toe Cylinder Position Sensor : Voltage Below Normal	A Level 2 warning will activate. The rear true track will be disabled. If there are no active faults on the Rear Steering Cylinder Position Sensor (3890-3, 3890-4 or 3890-8), the Rear Toe In Solenoid shall be commanded at full current to eliminate track binding and The Rear Steering Cylinder should not be allowed to retract below 39.9 mm if the fault is active. However, if there is an active fault on the Rear Steering Cylinder Position Sensor (3890-3, 3890-4 or 3890-8) the Rear Toe Out Solenoid shall be commanded at full current if the fault is active. This action will result in track binding, but is required to ensure an over center condition does not occur.
3891-8	Rear Toe Cylinder Position Sensor : Abnormal Frequency, Pulse Width, or Period	A Level 2 warning will activate. The rear true track will be disabled. If there are no active faults on the Rear Steering Cylinder Position Sensor (3890-3, 3890-4 or 3890-8), the Rear Toe In Solenoid shall be commanded at full current to eliminate track binding and The Rear Steering Cylinder should not be allowed to retract below 39.9 mm if the fault is active. However, if there is an active fault on the Rear Steering Cylinder Position Sensor (3890-3, 3890-4 or 3890-8) the Rear Toe Out Solenoid shall be commanded at full current if the fault is active. This action will result in track binding, but is required to ensure an over center condition does not occur.

Possible causes for an FMI 3 Diagnostic Code are:

The sensor has failed.
The sensor supply or the ground circuit in the machine harness is open.
The signal circuit in the machine harness is shorted to the +battery.
The signal circuit in the machine harness is open or the sensor is disconnected.
The ECM has failed. A failure of the ECM is unlikely.

Possible causes for an FMI 4 Diagnostic Code are:

The sensor has failed.
The signal circuit in the machine harness is shorted to ground.
The ECM has failed. A failure of the ECM is unlikely.

Possible causes for an FMI 8 Diagnostic Code are:

The sensor has failed.
The wrong sensor is installed.
Intermittent connections or poor connections.
The ECM has failed. A failure of the ECM is unlikely.

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Illustration 3	g06014250
Sensor Signal (PWM) Electrical Connections for the Steering ECM

Note: The diagram above is a simplified schematic of the Steering ECM. The schematic is electrically correct. However, not all the possible harness connectors are shown.Refer to the appropriate media number below for the complete Electrical Schematic: (S/N: JCF; LH9; 8RF; EL6) Machines refer to Electrical Schematic, UENR6397. (S/N: JB9; JFC; LB8; FG4; TPH; XS6) Machines refer to Electrical Schematic, UENR6398. (S/N: JB7; HN8; HC8; RL3; H6S; 626) Machines refer to Electrical Schematic, UENR8363. (S/N: SL8; TLZ; ESE; AK5; AN8; EE2; E8S; 3C6; 627) Machines refer to Electrical Schematic, UENR8362.The schematic will illustrate locations for all the electrical components and harness connectors that are installed on the machine.

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Table 8
Front Toe Cylinder Position Sensor DTC 3889 Cylinder Stroke 60 mm (2.36 inch) Frequency: 250 ±15 Hz
PWM %	Cylinder Position
5%	Fully Retracted
95%	Fully Extended

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Table 9
Rear Toe Cylinder Position Sensor DTC 3891 Cylinder Stroke 50 mm (1.97 inch) Frequency: 250 ±15 Hz
PWM %	Cylinder Position
5%	Fully Retracted
95%	Fully Extended

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Table 10
Front and Rear Steering Cylinder Position Sensors DTC 3888, 3890 Cylinder Stroke 435 mm (17.13 inch) Frequency: 250 ±15 Hz
PWM %	Cylinder Position
5%	Fully Retracted
95%	Fully Extended

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Table 11
Left Side Plate Front and Rear Cylinder Position Sensors DTC 3884, 3885 Cylinder Stroke 395 mm (15.55 inch) Frequency: 250 ±15 Hz
PWM %	Cylinder Position
5%	Fully Retracted
95%	Fully Extended

The tables above are references that can be used when checking the signal of the PWM sensors.

Diagnostic Trouble Code Procedure

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Table 12
Troubleshooting Test Steps	Values	Results
1. Identify Active FMI Code Associated With Sensor Circuit	Code present	FMI 3 diagnostic code, proceed to Test Step 2. FMI 4 diagnostic code, proceed to Test Step 6. FMI 8 diagnostic code, proceed to Test Step 8.
Begin Process For FMI 3 Troubleshooting HERE
2. Check The Control And The Harness A. Turn the key start switch and disconnect switch to the ON position. B. Disconnect the machine harness from the sensor. C. Refer to the schematic to determine the voltage source for the suspected faulty sensor. D. Measure voltage between signal and ground contacts at the machine harness connector for the sensor.	Voltage is 8.0 VDC ± 0.5 VDC or 24.0 VDC ± 1.0.	OK - The voltage reading is correct for the suspected faulty sensor. Proceed to Test Step 3. NOT OK- The voltage is NOT correct for the circuit. Repair - Refer to the diagnostic code procedure in this manual for troubleshooting of the power supply. After the power supply procedure is performed, verify the status of the sensor diagnostic code before proceeding. Proceed to Test Step 3.
3. Check For An Open In The Sensor Circuit A. The sensor remains disconnected from the machine harness. B. Turn the key start switch and the disconnect switch to the OFF position. C. At the harness connector for the sensor, place a jumper wire between Pin 2 (or Pin B) and Pin 3 (or Pin C). These locations are also referred to as the ground contact and the signal contact. D. Disconnect harness connectors from the ECM. E. At machine harness connector for sensor, measure the resistance from the signal contact to return contact. F. Gently pull on the wires and move the wires in a circular motion at ECM connector and observe the resistance readings. Repeat the process for the sensor connector.	The resistance is less than 5 Ω at all times during the manipulation of the harness.	OK - The resistance is less than 5 Ω. The signal circuit and the ground circuits of the sensor are not open in the machine harness. Proceed to Test Step 4. NOT OK - Resistance reading for the signal circuit or the return circuit is greater than 5 Ω. Repair: Check the signal circuit or the ground circuit for opens or bad connections. Repair or replace the machine harness, if necessary. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or a corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
4. Check Signal Circuit For A Short To +Battery A. The Sensor and the ECM are disconnected from the harness. B. Turn the disconnect switch and the key start switch to the OFF position. C. Measure the resistance between the signal and +battery contacts of the harness connector for the sensor. D. At machine harness connector, measure the resistance from signal contact to all possible sources of +battery.	Resistance is greater than 5K Ω for all readings.	OK - The resistance is greater than 5K Ω. The harness circuit is correct. Proceed to Test Step 5. NOT OK - The resistance less than 5 Ω. Repair: A short exists in the harness between the +battery and signal circuit. Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
5. Check The Harness For An Open A. The disconnect switch and key start switch are in the OFF position. B. The sensor and ECM are disconnected from the harness. C. Connect a jumper wire from the end of the signal wire at the ECM to a known ground. D. Measure the resistance of the signal wire at the ECM.	Resistance is less than 5 Ω.	OK - The resistance of the signal wire is less than 5 Ω. Proceed to Test Step 14. NOT OK - The resistance is greater than 5K Ω. The signal wire is open in the machine harness. Repair: Repair or replace the harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
Begin Process For FMI 4 Troubleshooting HERE
6. Check The Sensor A. With the FMI 4 diagnostic code active, disconnect the sensor from the machine harness. B. Observe Cat^® Electronic Technician (Cat ^®ET) or the operator monitor for code change as the sensor is disconnected and connected to the harness.	Code changes from FMI 4 to FMI 3.	OK - The FMI 4 diagnostic code remains active when sensor is disconnected. The sensor is not the cause of the problem. Proceed to Test Step 7. NOT OK - The diagnostic changed to an FMI 3 when the sensor was disconnected. Repair: Replace the sensor. STOP
7. Check The Signal Circuit For A Short To Ground A. Turn the key start switch and the disconnect switch to the OFF position. B. Disconnect the harness connector from the ECM. C. Measure the resistance between the signal contact for sensor and frame ground.	The resistance is greater than 5K Ω.	OK - The resistance is greater than 5K Ω. The harness circuit is correct. Proceed to Test Step 14. NOT OK - The resistance is less than 5 Ω. A short circuit exists between frame ground and the signal circuit. Repair: Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
Begin Process For FMI 8 Troubleshooting HERE
8. Check Harness For An Open A. Turn the disconnect switch and the key start switch to the OFF position. B. The sensor and ECM are disconnected from the harness. C. Connect a jumper wire from the end of signal wire at the ECM to a known ground. D. Measure the resistance of the signal wire at the ECM.	The reading is less than 5 Ω.	OK - The measurement is less than 5 Ω. Proceed to Test Step 9. NOT OK - The measurement is greater than 5K Ω. The signal circuit in the harness is open. Repair: Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or a corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
9. Check The Signal Circuit For A Short To Ground A. Turn key start switch and disconnect switch to the OFF position. B. Disconnect the harness connector from the ECM (or "Switch Panel"). C. Measure the resistance between the signal contact for the sensor and frame ground.	Reading is greater than 5K Ω.	OK - Measurement is greater than 5K Ω. Proceed to Test Step 10. NOT OK - Measurement is less than 5 Ω. The signal circuit in the harness is shorted to ground. Repair: Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
10. Check The Sensor For A Short To Case A. Turn the key start switch and the disconnect switch to the OFF position. B. At the machine harness connector for the sensor, measure the resistance between each contact of the sensor (1, 2, 3, or A, B, C). Connect the ground lead of the meter to an unpainted location on case of sensor.	The reading is greater than 5K Ω.	OK - All measurements are greater than 5K Ω. Proceed to Test Step 11. NOT OK - A measurement is less than 5 Ω. The sensor has failed. Repair: Replace the sensor. Confirm that the new sensor corrects the problem. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
11. Check The Sensor A. Turn the key start switch and the disconnect switch to the ON position. B. Use Cat ^® ET (or the operator monitor) to confirm the existence of the diagnostic code. C. Disconnect the sensor from machine harness.	The diagnostic code is no longer present.	OK - Diagnostic code is NO longer active. The sensor has failed. Repair: Replace the sensor. Verify new sensor corrected the diagnostic code. STOP NOT OK - The diagnostic code remains active. Proceed to Test Step 12.
12. Check If The Diagnostic Code Remains A. Turn the key start switch and the disconnect switch to the ON position. B. Clear all diagnostic codes. C. Operate the machine. D. Stop machine and engage the safety lock lever. E. Check if the diagnostic code for the sensor is active.	The code for the sensor is NO longer present.	OK - The diagnostic code does not exist at this time. The initial diagnostic code may have been caused by a poor electrical connection or a short at one of the harness connections. Resume machine operation. STOP NOT OK - The diagnostic trouble code has not been corrected. Repair: Recheck the circuit and perform this procedure again. If the diagnostic code is still active, the Machine ECM may require replacement. Prior to replacing the ECM, always contact the Technical Communicator at your dealership for possible consultation with AVSpare. This consultation may effect repair time. If replacement is recommended, follow the procedure in Troubleshooting, "ECM - Replace". STOP