158 RENR5042-02 Troubleshooting Section D. Thoroughly clean the terminals on both injectors and the harness connectors. C. Use a jumper wire to create a short circuit between the socket of the suspect injector and the common socket of the suspect injector. This will replace the engine wiring with a short circuit. E. Exchange the harness between the two injectors that share the common line. F. Turn the key switch to the ON position. D. Turn the key switch to the ON position. G. Perform the “Injector Solenoid Test” at least two times. E. Perform the “Injector Solenoid Test” at least two times. Expected Result: Expected Result:
Exchanging the harness between the two injectors caused the problem to move to the other injector on Cat ET. Cat ET displays “Short” for the cylinder with the jumper wire. Results: Results: OK – Cat ET displays “Short” for the cylinder with the jumper wire. The ECM is OK. OK – The injector may be faulty. Repair: Repair the engine harness or replace the engine harness, as required. Repair: Replace the faulty injector. Restore the wiring to the proper injectors. Verify that the repair eliminates the problem. Perform the “Injector Solenoid Test”. STOP. Verify that the repair eliminates the problem. Not OK – Cat ET does not display “Short” for the cylinder with the jumper wire.
The ECM is not OK. STOP. Repair: Perform the following procedure: Not OK There is a problem with the injector harness under the valve cover. 1. Remove the jumper wire and return the P2 wiring to the original configuration. Repair: Repair the injector harness or replace the injector harness under the valve cover. 2. Temporarily connect a test ECM. Verify that the repair eliminates the problem. 3. Perform the “Injector Solenoid Test”. STOP. If the test ECM fixes the problem, reconnect the suspect ECM. If the problem returns with the suspect ECM, replace the ECM. Verify that the repair eliminates the problem. Test Step 7. Check the ECM for an Open Circuit STOP. Test Step 8.
Check the Harness between the ECM and the Valve Cover Base for a Short Circuit Electrical shock hazard. The electronic unit injec- tor system uses 90-120 volts. A. Turn the key switch to the OFF position. A strong electrical shock hazard is present if the key switch is not turned off. Electrical shock hazard. The electronic unit injec- tor system uses 90-120 volts. B. Disconnect the P2 connector. Remove the two terminals for the suspect injector from the P2 connector. A. Turn the key switch to the OFF position. A strong electrical shock hazard is present if the key switch is not turned off.