320E and 323E Excavators Machine Electronic Control System MID 299, 5226-8 Caterpillar

Conditions Which Generate This Code:

Illustration 1	g06011363
Schematic of the "Swing Left Pilot Pressure" Sensor

This diagnostic code is associated with the "Swing Left Pilot Pressure" Sensor. The FMI 08 diagnostic code means that the ECM has determined that the signal frequency is not within the expected range.

The "Swing Left Pilot Pressure" Sensor has an output frequency of approximately 500 Hz. The duty cycle of the signal changes as the position of the machine is changed. The duty cycle varies from approximately 19% at the minimum position to approximately 77% at the maximum position. The duty cycle is approximately 48% at the center position.

The possible causes of this diagnostic code are listed:

• The "Swing Left Pilot Pressure" Sensor has failed.

• Intermittent connections or poor connections

• The Machine ECM has failed. An ECM failure is unlikely.

Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 5226 FMI 08 is active before performing this procedure.

Note: Use the 257-9140 Fluke Digital Multimeter or the equivalent for the measurements in this procedure.

Test Step 1. CHECK FOR POWER AT THE "Swing Left PRESSURE" SENSOR.

1. Do not disconnect the harness connector from the joystick.

2. Turn the key start switch and the disconnect switch to the ON position.

3. At the back of the harness connector for the joystick, insert a 7X-1710 Multimeter Probe along the voltage supply wire J850-WH(White).

4. Measure the voltage from the voltage supply wire (J850-WH(White)) to frame ground.

Expected Result:

The voltage is approximately 8 VDC.

Results:

• OK - The voltage is approximately 8 VDC. Proceed to Test Step 2.

• NOT OK - The voltage is not approximately 8 VDC. The circuit is open.

  Repair: Repair the machine harness or replace the machine harness.

  STOP

Test Step 2. CHECK THE SIGNAL CIRCUIT OF THE "Swing left Pilot PRESSURE" SENSOR FOR THE CORRECT DUTY CYCLE.

1. Turn the key start switch and the disconnect switch to the OFF position.

2. At the back of the harness connector for the sensor, remove the 7X-1710 Multimeter Probe from the supply wire (J850-WH(White)) and insert the probe along the signal wire M818-YL(Yellow).

3. At the back of the harness connector for the sensor, insert a 7X-1710 Multimeter Probe along the ground wire 993-BR(Brown).

4. Turn the disconnect switch and the key start switch to the ON position.

5. Monitor the duty cycle of the "Swing Left Pilot Pressure" Sensor with the 257-9140 Fluke Digital Multimeter.

6. Without disconnecting the joystick or the hardware associated with the joystick from the machine, move the joystick control through the entire range of motion.

   Note: On some machines, it may be necessary to start the engine to move the joystick control through the entire range of motion.

Expected Result:

The duty cycle value of the joystick control responds in the manner that is described at the beginning of this procedure.

Results:

• OK - The duty cycle value of the joystick control responds correctly. The "Swing Left Pilot Pressure" Sensor is operating correctly. Proceed to Test Step 3.

• NOT OK - The duty cycle value of the joystick control does not respond correctly. The "Swing Left Pilot Pressure" Sensor is not operating correctly.

  Repair: Replace the entire joystick.

  STOP

Test Step 3. CHECK THE SIGNAL CIRCUIT AT THE ECM FOR THE CORRECT DUTY CYCLE.

1. Turn the key start switch and the disconnect switch to the OFF position.

2. Insert the 7X-1710 Multimeter Probes into the back of the Cat Grade Control ECM connector along CN4-6 (wire M818-YL(Yellow)) and CN1-6 (wire 993-BR(Brown)).

3. Turn the disconnect switch and the key start switch to the ON position.

4. Monitor the duty cycle of the joystick control with the 257-9140 Fluke Digital Multimeter.

5. Without disconnecting the joystick or the hardware associated with the joystick from the machine, move the joystick through the entire range of motion.

   Note: On some machines, starting the engine may be necessary to move the joystick through the entire range of motion.

Expected Result:

The duty cycle value of the joystick control responds in the manner that is described at the beginning of this procedure.

Results:

• OK - The duty cycle value of the joystick control responds correctly. The joystick is operating correctly. Proceed to Test Step 4.

• NOT OK - The duty cycle value of the joystick control does not respond correctly. The harness has failed.

  Repair: Repair the machine harness or replace the machine harness.

  STOP

Test Step 4. CHECK THE SIGNAL CIRCUIT FOR A SHORT IN THE HARNESS.

1. The key start switch and the disconnect switch remain in the OFF position.

2. Disconnect the machine harness connectors from the joystick and the ECM.

3. Measure the resistance between contact CN4-6 (wire M818-YL(Yellow)) and all contacts that are used in the Cat Grade Control ECM wiring harness.

Expected Result:

The resistance is greater than 5000 ohms.

Results:

• OK - The resistance is greater than 5000 ohms. The circuit is correct. Proceed to Test Step 5.

• NOT OK - The resistance is less than 5 ohms. The signal circuit is shorted to another circuit in the harness.

  Repair: Repair the machine harness or replace the machine harness.

  STOP.

Test Step 5. CHECK IF THE DIAGNOSTIC CODE REMAINS.

1. Inspect the harness connectors and clean the contacts of the machine harness connectors.

2. Reconnect all harness connectors.

3. Turn the disconnect switch and the key start switch to the ON position.

4. Operate the machine.

5. Check the status of the CID 5226 FMI 08 diagnostic code.

Expected Result:

The CID 5226 FMI 08 diagnostic code is not active.

Results:

• OK - The CID 5226 FMI 08 diagnostic code is not active. The diagnostic code does not exist currently. The initial diagnostic code was probably caused by a poor connection or a short at one of the connectors that was disconnected and reconnected. Resume normal operation.

  STOP

• NOT OK - The CID 5226 FMI 08 diagnostic code is active.

  Repair: An ECM failure is unlikely. Exit this procedure and perform this procedure again. If the cause of the failure is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".

  STOP