416E, 420E and 430E Backhoe Loaders MID 039 - CID 3084 - FMI 03 Caterpillar

Conditions Which Generate This Code:

Illustration 1	g02116515
Schematic of the "AESC Enable Selection" switch

This diagnostic code is associated with the "AESC Enable Selection" switch. This switch has two inputs to the engine ECM: normally open circuit (wire 182-PU) and normally closed circuit (wire 181-GY). During normal operation, one switch input is open and the other input is grounded. This diagnostic code is detected when both switch inputs are in the open state at the same time.

The possible causes of this diagnostic code are listed:

• A short to the + battery terminal

• The circuit is open.

• The switch has failed.

• The ECM may have failed. This is unlikely.

Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 3084 FMI 03 is active before performing this procedure.

Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.

System Response:

A level 2 warning is generated.

Test Step 1. CHECK THE CIRCUIT FOR THE SWITCH.

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

2. Disconnect the J2 engine harness connector from the Engine ECM.

3. At the J1 engine harness connector, measure the resistance from contact J1-45 (wire 181-GY) to contact J1-46 (wire 182-PU) with the switch in the Enabled position and the Disabled position.

Expected Result:

The resistance should measure less than 5 ohms and more than 5000 ohms for each position of the switch.

Results:

• YES - The resistance is correct for each measurement. Proceed to Test Step 2.

Test Step 2. CHECK FOR A SHORT.

1. Disconnect the switch from the harness. Disconnect the J2 machine harness from the Engine ECM.

2. At the J1 machine harness connector, measure the resistance from contact J1-45 (wire 181-GY) and contact J1-46 (wire 182-PU) to all other J1 and J2 contacts.

Expected Result:

The resistance measurement should be greater than 5000 ohms for each measurement.

Results:

• OK - The resistance measurement is greater than 5000 ohms for each measurement.

  Repair: Replace the switch.

  Proceed to Test Step 3.

• NOT OK - The resistance measurement is not greater than 5000 ohms for one or more measurements.

  Repair: The short is in the circuit with the low resistance measurement. Repair the harness or replace the harness. Verify that the problem has been corrected.

  STOP

Test Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS

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

2. Reconnect all the 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 3084 FMI 03 diagnostic code.

Expected Result:

The CID 3084 FMI 03 diagnostic code is active.

Results:

• YES - The CID 3084 FMI 03 diagnostic code is active. The diagnostic code has not been corrected. The ECM may have failed.

  Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. See Troubleshooting, "Electronic Control Module (ECM) - Replace".

  STOP

• NO - The CID 3084 FMI 03 is not active. The diagnostic code does not exist at this time.

  Repair: The initial diagnostic code was probably caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.

  STOP