VALVE GP-CONTROL 1178826 - Caterpillar

There is a strong electrical shock hazard when the crankshaft is rotating. Do not touch wires that are associated with the ignition transformer circuit when the engine is cranking or running.
If there is an active diagnostic code that pertains to the circuit, perform the following steps:
Set the engine control to the OFF/RESET mode. Remove the electrical power from the engine.
Connect the Caterpillar Electronic Technician (ET) to the service tool connector on the terminal box.
Restore the electrical power to the engine. Set the engine control to the "STOP" mode. Then start the engine. Run the engine under normal operating conditions.
Monitor the "Active Diagnostic Code" screen on Cat ET while you pull on all harnesses and connectors for the circuit with the active code. If the harness is being pulled and the active diagnostic code disappears, there is a problem in the wiring or the connector.
If there are no active diagnostic codes that pertain to the circuit, perform the following test:
Run the engine under normal operating conditions.
Monitor the "Display Status" screen on Cat ET while you pull on all harnesses and connectors for the circuit. If the harness is being pulled and the reading changes erratically, there is a problem in the wiring or the connector.
If there are no active diagnostic codes and there are complaints about intermittent changes in speed or power cutouts, perform the following test:
Run the engine under normal operating conditions.
Listen for speed burps or power cutouts while the wiring and/or the connectors are pulled. If the harness is being pulled and the engine has a speed burp or a power cutout, there could be a problem in the wiring or the connector.Expected Result:The problem appears to be external to the harnesses and connectors. Pulling on the harness and the connectors has no effect on the active diagnostic code, component status, or engine performance.Results:
OK - Proceed to Test Step 5.
Not OK - Repair: Set the engine control to the OFF/RESET mode. Remove the electrical power from the engine. Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 5. Check Wires for Nicks or Abrasion in the Insulation
Set the engine control to the "STOP" mode. Allow the engine to coast to a stop.
Set the engine control to the "OFF/RESET" mode. Remove the electrical power from the engine.
Carefully inspect each wire for signs of abrasion, nicks, or cuts. The following areas are likely locations:
Places with exposed insulation
Points with wiring that rubs against the engine
Places with wiring that rubs against a sharp point
Check all of the hold down clamps for the harness in order to verify that the harness is properly clamped. Also, check all of the hold down clamps in order to verify that the harness is not compressed by the clamps. Pull back the harness sleeves in order to check for flattening of the wires by the clamps. Expected Result:The wires are free of abrasion, of nicks, and of cuts and the harness is properly clamped.Results:
OK - Proceed to Test Step 6.
Not OK - Repair: Repair the