Diagnosis & Repair
NOTE:
Read freeze frame data using hand-held tester or OBD II scan tool, as freeze frame data records engine conditions when malfunction is detected. When trouble shooting, it is useful for determining whether vehicle was running or stopped, engine was warmed up or not, air-fuel ratio was lean or rich, etc. at time of malfunction.
For wiring diagram, see Fig 1. For diagnosis and repair with hand-held tester, seeFig 2 and Fig 3 . For diagnosis and repair with OBD II scan tool, see Fig 4. To check for intermittent problems, see INTERMITTENT PROBLEM CHECK under SELF-DIAGNOSTIC SYSTEM. For removal of generator, see appropriate GENERATORS & REGULATORS article under CHARGING SYSTEM in ELECTRICAL. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article. For testing of components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. To check ECM inputs and outputs, see PIN VOLTAGE CHARTS article. To identify circuits referenced in testing, see ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.