Diagnostic Procedures
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2003 GMC Sonoma, 2003 GMC Safari, 2003 GMC Jimmy, 2003 Chevrolet S10 Pickup, and 2003 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.
- Perform Diagnostic System Check - Engine Controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 4.3L ASTRO, BLAZER, JIMMY CANDIAN, SAFARI, SONOMA & S10 PICKUP article. After performing Diagnostic System Check - Engine Controls, go to next step.
- Is DTC P0200 set? If yes, diagnose DTC P0200. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 4.3L ASTRO, BLAZER, JIMMY CANADIAN, SAFARI, SONOMA & S10 PICKUP article. If no, go to next step.
- Inspect PCM 1 fuse. Is PCM 1 fuse open? If yes, go to next step. If no, go to step 6.
- Turn ignition off. Disconnect fuel injectors multi-way harness connector. Using a test light connected to battery voltage, probe the ignition 1 voltage circuit of a fuel injector, fuse side. Does test light illuminate? If yes, go to step 8. If no, go to next step.
- Turn ignition on, with engine off. Does the test light illuminate? If yes, go to step 11. If no, go to DIAGNOSTIC AIDS .
- Turn ignition off. Disconnect fuel injectors multi-way harness connector. Turn ignition on, with engine off. Using test light connected to ground, probe the ignition 1 voltage circuit of the fuel injector, fuse side. Does the test light illuminate? If yes, go to next step. If no, go to step 9.
- Using a DVOM, measure the resistance from the PCM 1 fuse to the ignition 1 voltage circuit terminal. Is the resistance more than 5 ohms? If yes, go to step 10. If no, problem is intermittent.
- Repair ignition 1 voltage circuit of the fuel injectors for a short to ground. After repairs, go to step 12.
- Repair open in the ignition 1 voltage circuit of the fuel injectors. After repairs, go to step 12.
- Repair high resistance in the ignition 1 voltage circuit of the fuel injectors. After repairs, go to step 12.
- Repair short to a PCM ground in the ignition 1 voltage circuit of the fuel injectors. After repairs, go to next step.
- Operate the system in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step 3.