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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 83 (Engine Controls Self-Diagnostics - 2.2L) >> Diagnostic Tests >> DTC P0201-P0204: Injector Control Circuit >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2002 GMC Sonoma and 2002 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check, go to next step.
  2. Clear the DTCs with a scan tool. Idle the engine at the normal operating temperature. Monitor the misfire current counters, with a scan tool. Are any of the counters incrementing? If yes, go to step  4. If no, go to next step.
  3. Observe the Freeze Frame/Failure Records data for this DTC. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running the DTC or as close to the Freeze Frame/Failure Records data that you observed. See CONDITIONS FOR RUNNING DTC . Does the DTC fail this ignition? If yes, go to next step. If no, see DIAGNOSTIC AIDS .
  4. Turn ignition off. Disconnect the fuel injector harness multi-way connector. Probe the appropriate fuel injector control circuit, PCM side, with a test light connected to B+. Crank the engine. Does the test light flash when cranking the engine? If yes, go to step  8. If no, go to next step.
  5. Does test light remains illuminated at all times? If yes, go to step  7. If no, go to next step.
  6. Test the control circuit of the fuel injector for a short to voltage or an open between the multi-way connector and the PCM. Did you find and correct the condition? If yes, go to step  18. If no, go to step  14.
  7. Test the control circuit of the fuel injector for a short to ground between the multi-way connector and the PCM. Did you find and correct the condition? If yes, go to step  18. If no, go to step  17.
  8. Check the accessible fuel injector jumper harness between the multi-way connector and fuel injector for poor connections at multi-way connector, damaged or pinched wiring, or broken wires inside insulation. Did you find and correct the condition? If yes, go to step  18. If no, go to next step.
  9. Using a test light connected to battery voltage, probe the appropriate fuel injector control circuit at fuel injector side and at the multi-way connector. Does the test light illuminate? If yes, go to step  15. If no, go to next step.
  10. Using a DVOM, check for continuity between ignition voltage terminal and appropriate fuel injector control circuit terminal at the multi-way connector. Does the DMM indicate OL? If yes, go to next step. If no, go to step  13.
  11. Test the control circuit of the fuel injector for an open, or for poor connections at the fuel injector. Did you find and correct the condition? If yes, go to step  18. If no, go to next step.
  12. Test the ignition 1 voltage supply circuit of the fuel injector for an open between the fuel injector and the splice. Did you find and correct the condition? If yes, go to step  18. If no, go to step  16.
  13. Test the control circuit of the fuel injector for a short to voltage, or a short to another circuit. Did you find and correct the condition? If yes, go to step  18. If no, go to step  16.
  14. Check for poor connections at PCM harness connector. Did you find and correct the condition? If yes, go to step  18. If no, go to step  17.
  15. Repair short to ground in fuel injector control circuit. After repairs, go to step  18.
  16. Replace appropriate fuel injector. After replacing injector, go to step  18.
  17. Replace PCM. After replacing PCM, go to next step.
  18. Use the scan tool in order to clear the DTCs. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC . Does the DTC run and pass? If yes, go to next step. If no, go to step  2.
  19. With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
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