24M Motor Grader Power Train Electronic Control System MID 027 - CID 0679 - FMI 06 Caterpillar

Conditions Which Generate This Code:

Illustration 1	g02625575
Schematic of the Lockup Clutch Solenoid

The CID 0679 FMI 06 diagnostic code is associated with the Lockup Clutch Solenoid. The FMI 06 diagnostic code means that the ECM has detected that the current for the solenoid circuit is above normal.

The coil resistance for this solenoid is 8.7 ± 0.4 ohms at 25°C.

The possible causes of this diagnostic code are listed below:

• The energize circuit of the solenoid is shorted to ground.

• The solenoid has failed.

• The ECM has failed. This situation is unlikely.

Note: Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit meet the following requirements: clean, secure and good condition. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.

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.

Test Step 1. CHECK THE SOLENOID.

1. Turn the disconnect switch and the key start switch to the ON position. Do not start the machine when turning the key start switch.

2. Observe the status of the diagnostic code.

3. Disconnect the solenoid with the active diagnostic code from the machine harness.

Expected Result:

The CID 0679 FMI 06 changes to a CID 0679 FMI 05 when the solenoid is disconnected.

Results:

• YES - The active CID 0679 FMI 06 code changes to a CID 0679 FMI 05 code when the solenoid is disconnected. The solenoid circuit in the machine harness is correct.

  Repair: The solenoid has failed. Replace the solenoid. Verify that the new solenoid corrects the problem.

  STOP

• NO - The CID 0679 FMI 06 remains active. Disconnecting the solenoid did not change the status of the active diagnostic code. The solenoid is not the cause of the problem. Proceed to Test Step 2.

Test Step 2. CHECK THE ENERGIZE CIRCUIT OF THE SOLENOID FOR A SHORT TO GROUND.

The solenoid remains disconnected from the machine harness.

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

2. Disconnect the machine harness connectors J1 and J2 from the ECM.

3. At the machine harness connector, measure the resistance from the signal contact J2-48 (wire 705-PK) to frame ground. Measure the resistance from the signal contact J1-48 (wire 705-PK) to all of the other contacts that are used in J1 and J2 ECM connectors.

4. While observing the multimeter resistance measurements, wiggle the machine harness connectors for the ECM and the solenoid. Gently pull on the wires and move the wires all around.

Expected Result:

Each resistance measurement is greater than 5000 ohms at all times during the manipulation of the harness and connectors.

Results:

• OK - Each resistance measurement is greater than 5000 ohms. The machine harness is correct. Proceed to Test Step 3.

• NOT OK - Each resistance measurement is not greater than 5000 ohms. There is a short in the machine harness. The short is between J1-48 (wire 705-PK) and the circuit with the low resistance measurement.

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

  STOP

Test Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS.

1. Inspect the harness connectors and clean the contacts of the harness connectors. Check the wires for damage to the insulation that is caused by excessive heat, battery acid, or chafing.

2. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit.

3. Reconnect all harness connectors in order to make sure that the connectors are fully seated. Observe that the clips for each connector are fastened securely.

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

5. Operate the machine.

6. Check the status of the CID 0679 FMI 06 diagnostic code.

Expected Result:

The CID 0679 FMI 06 diagnostic code is active.

Results:

• YES - The CID 0679 FMI 06 code is active. The diagnostic code has not been corrected.

  Repair: Check the circuit again. If available, perform a ""Wiggle Test"" on the machine wiring harness use the Cat ""Electronic Technician (ET)"" service tool. The ""Wiggle Test"" can detect momentary short circuits or open circuits in the machine wiring harness.A failure of the ECM is unlikely. 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 0679 FMI 06 code 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. Resume normal machine operation.

  STOP