279C, 279C2, 289C, 289C2 and 299C Compact Track Loaders, 287C, 277C, 277C2, 287C2 and 297C Multi Terrain Loaders and 246C, 256C, 262C, 262C2 and 272C Skid Steer Loaders Machine Electronic Control System Caterpillar

Illustration 1	g01270821
Schematic of the Left Drive (Forward) Pump Solenoid Circuit

This diagnostic code is recorded when the ECM reads the voltage of the solenoid circuit as being above normal or shorted to +battery.

The possible causes of this diagnostic code are listed:

• The energize circuit of the solenoid is shorted to the +battery circuit.

• The ECM has failed. This is unlikely.

Note: Ensure that CID 1703 FMI 03 is on hold and that the diagnostic indicator is illuminated. The nominal coil resistance at room temperature is 4.1 ± .3 ohms.

System Response:

The action lamp will flash. The machine will be brought to a stop. The park brake will engage.

Test Step 1. CHECK THE SOLENOID CIRCUIT FOR A SHORT TO THE +BATTERY CIRCUIT.

1. Disconnect the negative battery cable and turn the key start switch to the OFF position.

2. Disconnect the machine harness from the solenoid.

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

4. At the machine harness connector, measure the resistance from signal contact J1-48 (wire K944-YL) to all contacts that are used in the machine harness connectors for the ECM.

Expected Result:

Each resistance measurement should be greater than 5000 ohms.

Results:

• OK - Each resistance measurement is greater than 5000 ohms. The machine harness is correct. Proceed to test step 2.

• NOT OK - One or more resistance measurements is not correct. There is a short in the machine harness. The short is between signal contact J1-48 (wire K944-YL) and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness.STOP

Test Step 2. CHECK IF THE DIAGNOSTIC CODE REMAINS.

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

2. Reconnect all harness connectors.

3. Reconnect the negative battery cable and turn the key start switch to the ON position.

4. Clear all of the logged diagnostic codes.

5. Operate the machine.

6. Check if the CID 1703 FMI 03 is present.

Expected Result:

The diagnostic code for the solenoid is NOT present.

Results:

• YES - The diagnostic code is NOT present. 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

• NO - 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. Also, recheck if the diagnostic indicator is illuminated for this diagnostic code. If the cause of the diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".

  STOP