Electronic Modular Control Panel II (EMCP II) For MUI Engines Caterpillar

Illustration 1	g00488088
System Schematic For Crank Termination Relay (CTR)

The GSC uses the crank termination relay (CTR) to activate the optional auxiliary relay (AUXREL). The CTR is located within the relay module. The AUXREL is located on the subpanel within the control panel.

The CTR is used to indicate that the engine is beginning to run without cranking. The GSC activates the CTR when the engine speed is greater than the crank terminate setpoint. (Setpoint P11 should be 400 RPM.) Also, the GSC activates the CTR when the starting motor relay has been deactivated. The CTR deactivates when the engine RPM reaches 0.

Note: Whenever the GSC activates the CTR, "K3" is shown on the lower display. "K3" is also shown on the lower display when the GSC attempts to activate the crank terminate relay. When the CTR is not activated, "K3" is not shown.

Procedure

The possible cause of this diagnostic code is an open coil or a shorted coil of the CTR.

The following response is the system response to this fault while the CTR is activated:

• If a CID 443 occurs while the CTR is activated, then the engine continues to run and the AUXREL is deactivated and the governor switch is deactivated.

• If a CID 443 occurs while the CTR is not activated, then the engine is ablr to start and run, but the AUXREL and the governor switch are not activated.

The following response is the system response to this fault while the CTR is not activated:

• If a CID 443 occurs, then the engine is able to start and the engine can run. The AUXREL is not activated.

The GSC treats a CID 443 as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed. Also, the active alarm faults are shown when the ECS is in any position except the OFF/RESET position. Clear the diagnostic code from the fault log after troubleshooting is complete.

1. Check the status of the diagnostic code (Active/Inactive).

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

   2. Press the alarm codes key.

   3. Observe the upper display. Check that aCID 443 FMI 12 is showing.

   4. If the diagnostic code is not showing, enter the service mode. View the fault log (OP1). Check that the diagnostic code is showing.

      Expected Result: A CID 443 FMI 12 is showing as a active fault or an inactive fault.

      Results:

      • No - A CID 443 FMI 12 has not occurred. STOP.

      • Yes - A CID 443 FMI 12 is active or inactive. Proceed to 2.

2. Check internal cable of relay module.

   Note: Only open the relay module in a dry environment. If the inspection takes more than twenty minutes replace the desiccant bag in the GSC housing. See Testing And Adjusting, "Relay Module Replace".

   1. Turn the ECS to OFF/RESET.

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

   3. 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 - Reassemble the relay module to the GSC. Proceed to 3.

      • NOT OK - Replace the connector clamp if it is missing. If the cable is damaged, replace the GSC. STOP.

3. Perform a functional check for the CTR.

   1. Turn the ECS to OFF/RESET.

   2. Disconnect all wires from RM-16 of the relay module.

   3. At the relay module, measure the resistance from RM-16 to RM-3. Resistance should be greater than 5000 ohms.

   4. Start the engine. Make sure that the engine speed is greater than the setpoint for crank termination (P11).

   5. At the relay module, measure the resistance from RM-16 to RM-3. Resistance should be less than 5 ohms.

      Expected Result: For 3.c, the resistance should be greater than 5000 ohms. For 3.e, the resistance should be less than 5 ohms.

      Results:

      • OK - It is likely that a temporary bad electrical connection existed and this troubleshooting procedure corrected it. Check the electrical connectors, terminals and wiring. See Testing And Adjusting, "Electrical Connector - Inspect". STOP.

      • NOT OK - Either one of the resistance measurements are NOT correct. The relay module is faulty. Replace the relay module. See Testing And Adjusting, "Relay Module - Replace". STOP.