G3412C, G3508, G3512 and G3516 Engines Status Control Module Caterpillar

Use this procedure if an shutdown fault occurs but the engine continues to run.

Test Step 1. Inspect Electrical Connectors and Wiring

1. Shut down the engine.

2. Turn the Engine Control Switch (ECS) to the OFF/RESET position.

3. Turn the main disconnect switch to the OFF position.

4. Thoroughly inspect all of the connectors that are associated with the circuit.

Expected Result:

All connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.

Results:

• OK - The harness and connectors appear to be OK. Proceed to Test Step 2.

• Not OK - There is a problem with the connectors and/or wiring.

  Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.

  STOP

Test Step 2. Check For Diagnostic Codes and Fault Indicators

1. Turn the main disconnect switch to the ON position.

2. Start the engine.

3. Check for diagnostic codes and fault indicators on the Status Control Module (SCM).

Expected Result:

There is a diagnostic code or a fault indicator that is displayed.

Results:

• OK - There is a diagnostic code or a fault indicator that is displayed. If the energize to Shutdown (ETS) fuel system is supported, go to Test Step 3.

• OK - There is a diagnostic code or a fault indicator that is displayed. If the energize to Run (ETR) fuel system is supported, go to Test Step 4.

• Not OK - There is not a diagnostic code or a fault indicator that is displayed. Proceed to Test Step 5.

Test Step 3. Check the ETS Fuel System

1. Measure the voltage at the following locations while the engine is running and the fault indicator(s) illuminated:
   • Terminal 23 at the SCM

   • Terminal S at the SCM

   • Terminal R at the SCM

Expected Result:

The voltage is above 20 VDC for all three measurements.

Results:

• OK - The voltage is above 20 VDC for all three measurements.

  Repair: There may be an open in the wire from the fuel solenoid to terminal 23 at the SCM.Repair the connectors or wiring and/or replace the connectors or wiring. If the wire is OK, troubleshoot the fuel solenoid.Verify that the repair eliminates the problem.

  STOP

• Not OK - The voltage is below 20 VDC at terminal 23. The voltage is above 20 VDC for the other measurements.

  Repair: There may be a problem with the Fuel Control Relay (FCR).Proceed to Testing and Adjusting, "Relay module - Test".

  STOP

• Not OK - The voltage is not below 20 VDC at terminal R. The voltage is below 20 VDC for the other measurements.

  Repair: Replace the fuse F6.There may be a problem in the wire harness between the fuel solenoid and the SCM.Repair the connectors or wiring and/or replace the connectors or wiring. Verify that the repair eliminates the problem.

  STOP

• Not OK - The voltage is below 20 VDC for all three measurements.

  Repair: There may be a problem in the wire harness between the +Battery and terminal R at the SCM.Repair the connectors or wiring and/or replace the connectors or wiring. Replace the battery, if necessary.Verify that the repair eliminates the problem.

  STOP

Test Step 4. Check the ETR Fuel System

Carefully remove the fuse F6.

Expected Result:

The engine shuts down.

Results:

• OK - The engine shuts down.

  Repair: Verify that the FCR is not stuck in the closed position.Check the resistance between terminal 23 and terminal S at the SCM.If the resistance is below 5 Ohms, proceed to Testing and Adjusting, "Relay module - Test".If the resistance is not below 5 Ohms, troubleshoot the circuit for the Gas Shutoff Valve (GSOV).Verify that the repair eliminates the problem.

  STOP

• Not OK - The engine does not shut down.

  Repair: The GSOV is stuck in the run position.Shut down the engine and troubleshoot the GSOV.Verify that the repair eliminates the problem.

  STOP

Test Step 5. Check the Setpoints

Check the setpoint programming.

Expected Result:

The setpoint programming is OK.

Results:

• OK - The setpoint programming is OK.

  Repair: There may be an intermittent problem.Inspect the electrical connectors and wiring.If necessary, repair the connectors or wiring and/or replace the connectors or wiring.Verify that the repair eliminates the problem.

  STOP

• Not OK - The setpoint programming is not OK.

  Repair: A setpoint(s) is programmed to ignore fault conditions.Reprogram the setpoints.Proceed to Testing and Adjusting, "Setpoint Programming".Verify that the repair eliminates the problem.

  STOP