Electronic Modular Control Panel II+ (EMCP II+) Caterpillar

Illustration 1	g00793846
System Schematic For Starting Motor Relay (SMR) For MUI Engines

Illustration 2	g00793852
System Schematic For Starting Motor Relay (SMR) For EUI Engines

The GSC+ uses the starting motor relay (SMR) to activate the starting motor magnetic switch (SMMS). The SMR is located within the relay module.

Note: Whenever the GSC+ activates or the GSC+ attempts to activate the SMR, "K4" is shown on the lower display. When the SMR is not activated, "K4" is not shown.

The possible cause of a CID 0444 FMI 12 is an open coil or a shorted coil of the SMR.

The system responses to this diagnostic code are listed below.

• If a CID 0444 FMI 12 occurs and the SMR is activated, then the engine stops cranking.

• If a CID 0444 FMI 12 occurs and the SMR is not activated, then the engine can not crank or the engine can not start. If the engine is already running, then the engine continues to run.

The GSC+ treats a CID 0444 FMI 12 as an alarm fault. Active alarm faults are shown on the display when the "Alarm Codes" key is pressed. The ECS can 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 0444 FMI 12 or the troubleshooting procedure is for an inactive CID 0444 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 0444 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 0444 FMI 12 is displayed as an active diagnostic code or CID 0444 FMI 12 is displayed as an inactive diagnostic code.

Results:

• OK - The CID 0444 FMI 12 is active or the CID 0444 FMI 12 is inactive. Proceed to test step 2.

• NOT OK - The CID 0444 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 relay module is open for more than twenty minutes replace the desiccant bag which is located within the housing of 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 SMR.

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

2. Reconnect the battery negative cable.

3. Disconnect all wires from RM-18 of the relay module.

4. Remove fuse "F4" from the relay module.

5. At the relay module, measure the resistance from RM-18 to RM-6. Make a note of the resistance measurement.

6. Turn the ECS to the START position. Quickly measure the resistance from RM-18 to RM-6. Measure the resistance before the starting motor relay achieves drop time because of the cycle crank time. Make a note of the resistance measurement.

Expected Result:

The initial resistance measurement after removing the wires and the fuse from the relay module should be greater than 5000 ohms. The resistance measurement should be less than 5 ohms before the starting motor relay achieves the drop time because of the cycle crank time.

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.