D6N Track-Type Tractor Caterpillar

Illustration 1	g02658899
Air Temperature Control panel schematic

Illustration 2	g01891880
Air Temperature Control panel location

A CID 2661 is associated with the air temperature control panel that is located in the control panel. An FMI 04 means the machine ECM has determined the voltage of the circuit is below normal.

Possible causes for this diagnostic code are:

• The control panel is not receiving power.

• The signal circuit is shorted to ground.

• The control panel has failed.

• Machine ECM failure. 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 2661 FMI 04 is active before performing this procedure.

Note: Use a digital multimeter for the measurements in this procedure.

Test Step 1. INSPECT THE CONTROL PANEL.

1. Perform a visual inspection of the control panel, the wiring for the control panel and the hardware that is associated with the control panel.

Expected Result:

There is no apparent damage to the control panel, the wiring for the control panel or the hardware that is associated with the control panel.

Results:

• YES - There is no apparent damage to the wiring or the hardware associated with the control panel. Go to Test Step 2.

• NO - There is apparent damage to the control panel, the wiring for the control panel or the hardware that is associated with the control panel.

  Repair: Replace the damaged part.

  Go to Test Step 4.

Test Step 2. CHECK FOR POWER AT THE CONTROL PANEL.

1. Do not disconnect the harness connector from the control panel.

2. At the back of the harness connector for the control panel, insert a multimeter probe along contact 1 (wire 124-GN) for the voltage supply.

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

4. Measure the voltage from contact 1 (wire 124-GN) to frame ground.

5. Make sure that the connection to the frame ground is clean and clear of dirt and rust.

Expected Result:

The voltage is approximately 24 VDC.

Results:

• YES - The voltage is approximately 24 VDC. Go to Test Step 3.

• NO - The voltage is not approximately 24 VDC. The circuit is open. The fuse for the control panel may have failed.

  Repair: Repair or replace the harness. Check the fuse for the control panel. Make sure that the fuse is secured and that the fuse has not failed.

  Go to Test Step 4.

Test Step 3. CHECK THE CONTROL PANEL CIRCUIT FOR a SHORT TO GROUND.

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

2. Disconnect the J1 connector of the machine harness at the ECM.

3. Insert a multimeter probe along contact J1-37 for the sensor signal.

4. Measure the resistance from the signal contact J1-37 (wire A524-BR) to frame ground and all contacts that are used in the machine harness connectors for the ECM.

Expected Result:

The resistance is greater than 5000 ohms.

Results:

• YES - The resistance is greater than 5000 ohms. The signal circuit is correct. Go to Test Step 4.

• NO - The signal circuit is shorted to another circuit in the machine harness.

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

  STOP

Test Step 4. CHECK THE DIAGNOSTIC CODE STATUS.

1. Reconnect all harness connectors. Make sure that the connectors are clean and fully seated. Observe that the clips on each connector are securely fastened.

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

3. Operate the machine.

4. Clear all inactive diagnostic codes.

5. Check the status of the CID 2661 FMI 04 diagnostic code.

Expected Result:

The diagnostic code is no longer active.

Results:

• YES - The diagnostic code is no longer active and does not exist at this time. Return machine to normal operationSTOP

• NO - The diagnostic code is still active. The cause for the code has not been corrected.

  Repair: If you have not inspected the harness connectors in a previous Test Step, do that now. Clean the contacts of the harness connectors. Check the wires for damage to the insulation caused by excessive heat, battery acid, or chafing.Perform a 45 N (10 lb.) pull test on each of the wires that are associated with the sensor circuit.Perform a "wiggle test" on the sensor circuit of the machine wiring harness, using the Caterpillar Electronic Technician service tool. The "wiggle test" can be used to detect open or shorted connections in the machine wiring harness.Reconnect all harness connectors. Make sure that the connectors are fully seated. Observe that the clips for each connector are securely fastened. Perform Test Step 4 again. If the problem has NOT been found, and the original code is still active, the Scraper Transmission ECM may have failed.Prior to replacing an ECM, always contact your Dealership Technical Communicator for possible consultation with Caterpillar, or with the Dealer Solutions Network. This consultation may greatly reduce repair time. If the ECM needs to be replaced, see Testing and Adjusting, "Electronic Control Module (ECM) - Replace".

  STOP