LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chevrolet >> 2001 >> Prizm Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Basic Diagnostic Procedures >> Fuel Systems >> Fuel Injector Circuit Diagnosis >> Metro
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Fuel Injector Circuit Diagnosis: Metro

  1. Perform diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK in SELF-DIAGNOSTICS - METRO article. Repair any faults identified and go to next step.
    2. CAUTION: Ensure Malfunction Indicator Light (MIL) and Data Link Connector (DLC) function properly. See MIL INOPERATIVE, MIL ON STEADY and/or DATA LINK CONNECTOR DIAGNOSIS under CIRCUIT TESTS in SELF-DIAGNOSTICS - METRO article.
  2. Turn ignition off. Disconnect all 4 fuel injector electrical connectors. Install Injector Test light (J-34730-2B) in each fuel injector harness connector. While cranking engine, observe injector test lamps. If injector test lamps do not flash for each injector while cranking engine, go to next step. If injector test lamps do flash for each injector while cranking engine, check fuel injector coils. See SYSTEM & COMPONENT TESTING - CARS - METRO & PRIZM article.
  3. If any injector test light was illuminated all the time while cranking engine in step  2, go to next step. If no injector test light was illuminated all the time while cranking engine in step  2, go to step  5.
  4. Check for short to ground in injector control circuit (Brown/White wire for injector No. 1; Brown/Red wire for injector No. 2; Brown/Yellow wire for injector No. 3; Brown/Black wire for injector No. 4) between PCM connector C1 and any injector which illuminated the test light all the time while cranking engine in step  2. See WIRING DIAGRAMS article. Locate and repair short to ground in identified circuit as required. If no short to ground was identified and repaired, go to step  10. If short to ground was identified and repaired, go to step  11.
  5. Remove fuel injector test lamps from fuel injector electrical connectors. Connect a test light between ground and White/Blue wire of fuel injector harness connector that did not flash in step  2. Turn ignition on (engine off). If test light illuminates, go to next step. If test light does not illuminate, go to step  8.
  6. Connect one lead of a test light to control side of fuel injector harness connector that did not flash in step  2. See WIRING DIAGRAMS article. Connect other lead of test light to battery voltage. Observe test light while cranking engine. If test light flashes while cranking engine, go to next step. If test light does not flash while cranking engine, go to step  9.
  7. Repair faulty electrical connections at identified fuel injector harness connector. See WIRING DIAGRAMS article. After repair, go to step  11.
  8. Locate and repair open in White/Blue wire between identified fuel injector and main relay. Main relay is located in relay box. Relay box is located on left side of engine compartment, behind battery. After repair, go to step  11.
  9. Locate and repair open in control circuit (Brown/White wire for injector No. 1; Brown/Red wire for injector No. 2; Brown/Yellow wire for injector No. 3; Brown/Black wire for injector No. 4) between faulty fuel injector and PCM connector C1. See WIRING DIAGRAMS article. Repeat steps  2 through  9 until injector test light flashes in all 4 injector circuits. If no open was located and repair was not necessary, go to next step. If open was located and repaired, go to step  11.
  10. Replace PCM. After repair, reprogram PCM and go to next step. See PROGRAMMING in SELF-DIAGNOSTICS - METRO article.
  11. Operate vehicle under same conditions as recorded for original symptom. If system operates properly, system is okay at this time. If system does not operate properly, check for presence of water contamination of fuel, faulty injector spray pattern, leaking or stuck closed fuel injector, incorrect amount of fuel delivered by fuel injector, fuel injector resistance, and faulty camshaft timing belt installation or operation. An engine with no injector pulse on 2 injectors while cranking engine may have incorrect valve timing. Incorrect valve timing can affect phasing of crankshaft and camshaft position sensors, resulting in no fuel injector pulse to the fuel injectors. See SYSTEM & COMPONENT TESTING - CARS - METRO & PRIZM article.
scientia non olet · About LEMON Manuals