Diagnostic Aids

To locate intermittent problem, start engine and use scan tool to monitor INJECTORS 1-4 LOW VOLT, OPEN and HIGH VOLT tests. When an open or short to ground fault exists, scan tool will display TEST FAIL for both the LOW VOLT and OPEN tests. When a short to voltage or shorted solenoid fault exists, scan tool will display TEST FAIL for the HIGH VOLT test.

The LOW VOLT and OPEN tests will fail only when the device is being commanded off and voltage at PCM is low. The HIGH VOLT test will fail only when device being commanded on and voltage at PCM is high. All 3 tests update every 100 milliseconds. Injector resistance should be 11.8-12.6 ohms at 74°F (23°C).

When diagnosing an intermittent problem, use scan tool to review malfunction history diagnostic information. This data can be used to duplicate a problem. Check tightness to harness connector terminals. An open or shorted injector circuit will cause a misfire DTC. Diagnose an injector DTC first if an injector and misfire DTC is present. Fuel in the oil is a good suspect of a leaking or grounded injector. Battery voltage is supplied to each injector when ignition is on. Injector resistance should be 12 ohms.