Diagnostic Procedures

Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. After performing OBD system check, go to next step.
Operate engine at idle. Using scan tool, observe SPECIFIC DTC INFO for this DTC. If scan tool indicates that this DTC failed this ignition, go to step 4. If scan tool does not indicate that this DTC failed this ignition, go to next step.
Using scan tool, review and record FAIL RECORDS data. Operate vehicle within fail records conditions. Monitor SPECIFIC DTC INFO for this DTC until test runs. If scan tool indicates that this DTC failed this ignition, go to next step. If scan tool does not indicate that this DTC failed this ignition, see DIAGNOSTIC AIDS .
Check if DTCs P0201, P0204 and P0206 are also set. If these DTCs are set, go to next step. If these DTCs are not set, go to step 7.
Check for blown injector fuse. If fuse is blown, go to next step. If fuse is not blown, go to step 15.
Remove injector fuse. Using a DVOM, check for short between injector ignition feed circuit and chassis ground or injector control circuits. Repair as necessary. After repairs, go to step 18. If circuit is okay, perform injector coil test. See FUEL SYSTEM in appropriate SYSTEM & COMPONENT TESTING article.
Disconnect fuel injector harness connector. Turn ignition on, with engine off. Connect DVOM between chassis ground and affected injector harness connector ignition feed circuit. If voltage reading is about battery voltage, go to next step. If voltage reading is not about battery voltage, go to step 13.
Leave injector connector disconnected. Turn ignition off. Disconnect PCM harness connector. Turn ignition on, with engine off. Connect DVOM between chassis ground and affected fuel injector control circuit in PCM harness connector. If voltage reading is about battery voltage, go to step 14. If voltage reading is not about battery voltage, go to next step.
Turn ignition off. Check for open or short to ground in affected injector control circuit. Repair as necessary. After repairs, go to step 18. If circuit is okay, go to next step.
Reconnect fuel injector harness connector. Leave PCM harness connector disconnected. Turn ignition on, with engine off. Check voltage between ground and affected injector control circuit. If voltage reading is about battery voltage, go to next step. If voltage reading is not about battery voltage, go to step 12.
Check for poor connection at PCM. Repair as necessary. After repairs, go to step 18. If connection is okay, go to step 17.
Check for poor connection at affected fuel injector. Repair as necessary. After repairs, go to step 18. If connection is okay, go to step 16.
Repair open circuit or faulty splice connection in fuel injector feed circuit. After repairs, go to step 18.
Repair short to voltage in fuel injector control circuit. After repairs, go to step 18.
Repair open or faulty splice connections in fuel injector feed circuit. After repairs, go to step 18.
Replace affected fuel injector. After replacing injector, go to step 18.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, review and record FAIL RECORDS data. Clear DTCs. Operate vehicle within fail records conditions. Monitor SPECIFIC DTC INFO for this DTC until test runs. If scan tool indicates that this failed this ignition, go to step 2. If scan tool does not indicate that this DTC failed this ignition, system is okay.