Electronic Modular Control Panel II (EMCP II) Caterpillar

The GSC uses the generator fault relay (GFR) in order to activate the circuit breaker for the shunt trip coil during a shutdown fault. The GFR is located within the relay module. The circuit breaker is located in the load panel.

Note: Whenever the GSC activates or the GSC attempts to activate the GFR, "K2" is shown on the lower display. When the GFR is not activated, "K2" is not shown.

The possible cause of a CID 0442 FMI 12 is an open coil or a shorted coil of the GFR.

The system response to this diagnostic code is listed below.

• When a CID 0442 FMI 12 occurs and the GFR is activated, the diagnostic code will not have an effect on the system. The system is not affected because the optional circuit breaker is already open and shutdown mode is functioning. The generator is already off-line.

• If a CID 0442 FMI 12 occurs and the GFR is not activated, the GFR cannot activate the shunt trip coil of the optional circuit breaker when a shutdown fault occurs.

The GSC treats a CID 0442 FMI 12 as an alarm fault. Active alarm faults are shown on the display when the "Alarm Codes" key is pressed. The ECS must be in any position except the OFF/RESET position. Clear the diagnostic code from the fault log after troubleshooting is complete.

This troubleshooting procedure is for an active CID 0442 FMI 12 or the troubleshooting procedure is for an inactive CID 0442 FMI 12.

Test Step 1. CHECK THE STATUS OF THE DIAGNOSTIC CODE.

1. Turn the ECS to the OFF/RESET position and then turn the ECS to the STOP position.

2. Press the "Alarm Codes" key.

3. Observe the upper display. Check that the CID 0442 FMI 12 is active.

4. If the diagnostic code is not active, enter the Service Mode. View the fault log for a OP1. Check that the diagnostic code is inactive.

Expected Result:

A CID 0442 FMI 12 is displayed as an active diagnostic code or CID 0442 FMI 12 is displayed as an inactive diagnostic code.

Results:

• OK - The CID 0442 FMI 12 is active or the CID 0442 FMI 12 is inactive. Proceed to test step 2.

• NOT OK - The CID 0442 FMI 12 has not occurred. The diagnostic code is not active and the diagnostic code is not inactive. Stop.

Test Step 2. CHECK THE INTERNAL CABLE OF THE RELAY MODULE.

Note: Only open the relay module in a dry environment. If the inspection and the repair is over twenty minutes, replace the desiccant bag inside the GSC. See Testing And Adjusting, "Relay Module - Replace".

1. Turn the ECS to the OFF/RESET position.

2. Disconnect the battery negative cable.

3. Temporarily, remove the relay module from the GSC. See Testing And Adjusting, "Relay Module - Replace".

4. Check the cable that attaches the relay module to the GSC.

Expected Result:

The cable should be firmly seated in the connector. The clamp should be in place. The cable should not be damaged.

Results:

• OK - The cable is firmly seated in the connector. The clamp is in place. The cable is not damaged. Reassemble the relay module to the GSC. Proceed to test step 3.

• NOT OK - One or more of the components are damaged or the components are missing.

  Repair: Replace the clamp if the clamp is missing. If the cable is damaged, replace the GSC. See Testing and Adjusting, "EMCP Electronic Control (Generator Set) - Replace".

  Stop.

Test Step 3. PERFORM A FUNCTIONAL CHECK ON THE GFR.

1. Turn the ECS to the OFF/RESET position.

2. Reconnect the battery negative cable.

3. Disconnect all wires from RM-22 of the relay module.

4. Remove fuse "F5" from the relay module.

5. At the relay module, measure the resistance from RM-22 to RM-7. Make a note of the resistance measurement.

6. Turn the ECS to the STOP position and push in the emergency stop push button.

7. At the relay module, measure the resistance from RM-22 to RM-7. Make a note of the resistance measurement.

Expected Result:

The initial resistance measurement after removing the wires from the relay module should be 5000 ohms. The resistance measurement should be less than 5 ohms when the ECS is placed in the STOP position.

Results:

• OK - The resistance measurements are correct. The problem does not exist at this time. The initial problem was probably caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. Resume normal operation and watch for a recurrence. Stop.

• NOT OK - Either one of the resistance measurements are NOT correct. The relay module has failed.

  Repair: Replace the relay module. See Testing And Adjusting, "Relay Module - Replace".

  Stop.