AIR CONDITIONER GP 4690020 - Caterpillar

Illustration 6 g01161304
Terminal locations at the connector for the injector harness at the valve cover
(Terminal 1) Injector 1 return
(Terminal 2) Injector 2 return
(Terminal 3) Injector 3 return
(Terminal 4) Injector 4 return
(Terminal 5) Injector 5 return
(Terminal 6) Injector 6 return
(Terminal 7) Injector 1 & 2 supply
(Terminal 8) Injector 3 & 4 supply
(Terminal 9) Injector 5 & 6 supply
Insert one end of the jumper wire into the connector socket for the suspect injector supply wire. Insert the other end of the jumper wire into the connector socket for the suspect injector return wire at the harness connector. This will effectively replace the injector solenoid with a short circuit.
Restore electrical power to the engine ECM.
Turn the keyswitch to the ON position.
Perform the "Injector Solenoid Test" at least two times.
Repeat this test for each suspect circuit. Stop the "Injector Solenoid Test" before handling the jumper wire. Restore the wiring to the original configuration.Expected Result:Cat ET displays "Short" for each of the circuits that were jumpered.Results:
OK - Cat ET displays "Short" for each circuit that was jumpered. The harness between the ECM and the injector harness connector does not have an open circuit. Proceed to Test Step 7.
Not OK - Cat ET displays "Open" for the cylinder with the jumper wire. There is a problem in the wiring between the ECM and the injector harness connector at the valve cover base. Proceed to Test Step 8.Test Step 6. Check the Harness between the ECM and the Valve Cover Base for a Short Circuit
Electrical shock hazard. The electronic unit injector system uses 90-120 volts.
Turn the keyswitch to the OFF position.
Remove electrical power from the engine ECM.
Disconnect the connector for the injector harness at the valve cover.
Restore electrical power to the engine ECM.
Turn the keyswitch to the ON position.
Perform the "Injector Solenoid Test" at least two times.Expected Result:All the cylinders indicate "Open" on Cat ET.Results:
OK - All cylinders indicate "Open" on Cat ET. The harness between the ECM and the connector for the injector harness at the valve cover does not have a short circuit. Proceed to Test Step 7.
Not OK - One or more cylinders indicate "Short" on Cat ET. Note the cylinders that indicate "Short". Proceed to Test Step 8.Test Step 7. Check the Injector Harness Under the Valve Cover for an Open Circuit or for a Short Circuit
Electrical shock hazard. The electronic unit injector system uses 90-120 volts.
Turn the keyswitch to the OFF position.
Remove electrical power from the engine ECM.
Remove the valve cover to gain access to the suspect injector.
Disconnect the harness connector from the suspect injector.
Illustration 7 g01147088
Connector terminals for the injector solenoid
Thoroughly clean the terminals on the injector solenoid and on the harness connector.
Use a jumper wire to short circuit the connector terminals for the suspect injector. This will effectively replace the injector solenoid with a short circuit.
Restore electrical power to the engine ECM.
Turn the keyswitch to the ON position.
Perform the "Injector Solenoid Test" at least two times.Note: The injector solenoid that shares the supply wire of the injector that is short