Diagnostic Procedures
- Perform Diagnostic System Check - Engine Controls. See DIAGNOSTIC SYSTEM CHECK -- ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 3.4L MONTANA, SILHOUETTE & VENTURE article. After performing Diagnostic System Check - Engine Controls, go to next step.
- Are any fuel injector DTCs set? If yes, go to DTC P0200-P0206: FUEL INJECTOR CONTROL CIRCUITS in SELF-DIAGNOSTICS - 3.4L MONTANA, SILHOUETTE & VENTURE article. If no, go to next step.
- Inspect fuel injector fuse. Is fuel injector fuse open? If yes, go to next step. If no, go to step 6 .
- Turn ignition off. Disconnect the multi-way harness connector of the fuel injectors. Using a test light connected to battery voltage, probe the fuse side of the ignition 1 voltage circuit. Does the test light illuminate? If yes, go to step 9 . If no, go to next step.
- Turn ignition on, with engine off. Does test light illuminate? If yes, go to step 13 . If no, go to step 8 .
- Turn ignition off. Disconnect the multi-way harness connector of the fuel injectors. Turn ignition on, with engine off. Using a test light connected to ground, probe the fuse side of the ignition 1 voltage circuit of the fuel injector. Does the test light illuminate? If yes, go to next step. If no, go to step 10 .
- Using a DVOM, test for continuity between the ignition voltage terminal and a fuel injector terminal, at the multi-way harness connector, fuel injector side. Is resistance greater than 5 ohms? If yes, go to step 11 . If no, go to step 12 .
- Test the ignition 1 voltage circuit of the fuel injector, between the multi-way harness connector and the fuel injectors for a short to ground. Did you find and correct the condition? If yes, go to step 14 . If no, problem is intermittent.
- Repair short to ground in the ignition voltage circuit of the fuel injector. After repairs, go to step 14 .
- Repair open in the ignition 1 voltage between UBEC and the multi-way connector. After repairs, go to step 14 .
- Repair ignition 1 voltage circuit of the fuel injectors for an open and/or high resistance, between the multi-way connector and the splice. After repairs, go to step 14 .
- Repair poor connection at the multi-way connector. After repairs, go to step 14 .
- Repair short to a PCM ground in the ignition voltage circuit of the fuel injector. After repairs, go to next step.
- Operate the system in order to verify repair. Did you correct the condition? If yes, system is okay. If no, go to step 3 .