RENR5042-02 157 Troubleshooting Section B. Allow the engine to warm up to normal operating temperature. A. Turn the key switch to the OFF position. A strong electrical shock hazard is present if the key switch is not turned off. C. Stop the engine. B. Disconnect the connector from the valve cover base. D. Turn the key switch to the ON position. E. Access the “Injector Solenoid Test” by accessing the following display screens in order: C. Turn the key switch to the ON position. “Diagnostics” D. Fabricate a jumper wire 100 mm (4 inch) long with Deutsch pins on both ends of the wire. “Diagnostic Tests” E.
Insert one end of the jumper wire into the common socket for the suspect injector on the harness connector. Insert the other end of the jumper wire into the socket for the suspect injector on the harness connector. “Injector Solenoid Test” F. Activate the test. Note: Do not confuse the “Injector Solenoid Test” with the “Cylinder Cutout Test”. The “Cylinder Cutout Test” is used to shut off fuel to a specific cylinder while the engine is running. The “Injector Solenoid Test” is used to actuate the injector solenoids. This allows the click of the injector solenoids to be heard when the engine is not running in order to determine that the circuit is functioning properly. F.
Perform the “Injector Solenoid Test” at least two times. G. Repeat this test for each suspect injector. Stop the “Injector Solenoid Test” before handling the jumper wires. Expected Result: G. As each solenoid is energized by the ECM, an audible click can be heard at the valve cover. Cat ET displays “Short” for the cylinder with the jumper wire. H. Perform the “Injector Solenoid Test” at least two times. Results: Expected Result: OK The harness between the ECM and the valve cover base is OK. Proceed to Test Step 6. All cylinders indicate Not OK There is a problem between the ECM and the valve cover base. Proceed to Test Step 7. Results:
OK – There is not an electronic problem with the injectors at this time. Test Step 6. Check the Injector Harness under the Valve Cover Repair: If the “Cylinder Cutout Test” returned a “Not OK” for any injector, refer to Troubleshooting, “Engine Misfires, Runs Rough or Is Unstable”. Electrical shock hazard. The electronic unit injec- tor system uses 90-120 volts. STOP. Open Note the cylinders that indicate “Open”. Proceed to Test Step 5. A. Turn the key switch to the OFF position. A strong electrical shock hazard is present if the key switch is not turned off. Short Note the cylinders that indicate “Short”. Proceed to Test Step 8. B. Remove the valve cover. C.
Disconnect the harness from the suspect injector. Disconnect the harness from the injector that shares the same injector common line. Test Step 5. Check the Harness Between the ECM and the Valve Cover Base for an Open Circuit Note: If both injectors that share a common wire indicate “Open”, inspect the common wire under the valve cover for problems. The open circuit is probably caused by an open in the common wire. Electrical shock hazard. The electronic unit injec- tor system uses 90-120 volts.