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Home >> Chevrolet >> 2000 >> Prizm Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Circuit Tests >> Fuel Injector Circuit (1.3L) >> Diagnostic Procedure

Diagnostic Procedure

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article. After performing OBD system check, go to next step.
  2. Turn ignition off. Disconnect all 4 fuel injector electrical connectors. Install Fuel Injector Test Light (J-34730-2B) on each fuel injector harness connector. Crank engine and observe test light for each injector. If test light flashes for each injector while cranking engine, go to next step. If test light does not flash for each injector, go to step  5.
  3. Using DVOM, measure resistance of each fuel injector (fuel injector side). If resistance is 12-13 ohms at 68°F (20°C), go to next step. If resistance is not 12-13 ohms at 68°F (20°C), go to step  10.
  4. Check for fuel restrictions or for a partly blocked fuel injector nozzle. Repair as necessary. After repairs, go to step  17. If no fuel restriction was found or fuel injector nozzle is okay, check fuel system electrical circuit. See FUEL PUMP ELECTRICAL CIRCUIT test under appropriate NO START - ENGINE CRANKS OKAY under NO START DIAGNOSIS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  5. If test light remains illuminated on any injector while cranking engine, go to next step. If test light does not remain illuminated on any injector, go to step  7.
  6. Check for short to ground in fuel injector control circuit between fuel injector and PCM. Repair as necessary. After repairs, go to step  17. If circuit is okay, go to step  12.
  7. Remove test light from fuel injector harness connector. Turn ignition on, engine off. Using a DVOM, measure voltage between ground and ignition feed circuit at fuel injector connector (harness side). See appropriate wiring diagram in WIRING DIAGRAMS article. If battery voltage is present, go to next step. If battery voltage is not present, go to step  13.
  8. Connect test light between battery voltage and fuel injector control circuit at fuel injector connector (harness side). See appropriate wiring diagram in WIRING DIAGRAMS article. Crank engine and observe test light. If test light flashes while cranking engine, go to next step. If test light does not flash, go to step  11.
  9. Check for poor connection at fuel injector harness connector. Repair as necessary. After repairs, go to step  17. If connection is okay, go to next step.
  10. Replace fuel injector. After repairs, go to step  17.
  11. Check for an open in fuel injector control circuit. Repair as necessary. After repairs, go to step  17. If circuit is okay, go to next step.
  12. Replace PCM. After repairs, go to step  17.
  13. Turn ignition on, engine off. Using DVOM connected to ground, backprobe ignition feed circuit at fuel injector resistor connector (harness side). See appropriate wiring diagram in WIRING DIAGRAMS article. If battery voltage is present, go to next step. If battery voltage is not present, go to step  15.
  14. Check for an open or short to ground in ignition feed circuit between fuel injector and fuel injector resistor. Repair as necessary. After repairs, go to step  17. If circuit is okay, go to step  16.
  15. Repair open in ignition feed circuit between fuel injector resistor and main relay. After repairs, go to step  17.
  16. Replace fuel injector resistor. After repairs, go to next step.
  17. After repairs, operate vehicle within conditions under which original symptom was observed. If system operates properly, repair is complete. If system does not operate properly, see DIAGNOSTIC AIDS .
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