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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 370 (Engine Control System - Self-Diagnostics - 4.2L) >> Diagnostic Tests >> DTC P1682: Driver 5; Line 2 >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
  1. Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, see DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
    2. NOTE: Operating the throttle blade with the throttle blade control function of scan tool may cause additional DTCs to set. Do not attempt to diagnose DTCs set during this function.
  2. Turn ignition on, with engine off. With scan tool, command the throttle blade to 100 percent and back to zero percent. Exit the throttle blade control function. Did the throttle blade angle follow the commanded angle? If yes, go to next step. If no, go to step  4.
  3. Observe the Freeze Frame/Failure Records data for this DTC. Turn ignition off for 30 seconds. Start engine. Operate vehicle within the Conditions For Running 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 cycle? If yes, go to next step. If no, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 4.2L BRAVADA, ENVOY, ENVOY XL, TRAILBLAZER & TRAILBLAZER EXT article.
  4. With a test light connected to ground, probe both sides of the ETC fuse. Does the test light illuminate on both sides of the fuse? If yes, go to next step. If no, go to step  6.
  5. With a test light connected to ground, probe both sides of the PCM fuse. Does the test light illuminate on both sides of the fuse? If yes, go to step  10. If no, go to step  8.
  6. Test the ETC ignition 1 voltage circuit for a short to ground. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  7. Test the supply voltage to the ETC fuse for an open or high resistance. If a short to ground is found, replace affected fuse. Did you find and correct the condition? If yes, go to step  16. If no, go to step  10.
  8. Test the PCM ignition 1 voltage circuit for a short to ground. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  9. Test the supply voltage to the PCM fuse for an open or high resistance. If a short to ground is found, replace the affected fuse. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  10. Disconnect the PCM connector containing the ETC ignition 1 voltage. With a DVOM connected to ground, measure the voltage on the ETC ignition 1 voltage circuit. Does the voltage measure about 12 volts? If yes, go to next step. If no, go to step  12.
  11. Disconnect the PCM connector containing the PCM ignition 1 voltage. With a DVOM connected to ground, measure the voltage on the PCM ignition 1 voltage circuit. Does the voltage measure about 12 volts? If yes, go to step  14. If no, go to step  13.
  12. Test the ETC ignition 1 voltage circuit for an open or high resistance. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  13. Test the PCM ignition 1 voltage circuit for an open or high resistance. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  14. Test for poor connections at the PCM connectors. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  15. Replace PCM. See REMOVAL & INSTALLATION - BRAVADA, ENVOY, ENVOY XL, TRAILBLAZER & TRAILBLAZER EXT article. Reprogram PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repairs, go to next step.
  16. Clear the DTCs with scan tool. Turn ignition off for 30 seconds. Start engine. Operate vehicle within the Conditions For Running DTC. See CONDITIONS FOR RUNNING DTC . Does the DTC run and pass? If yes, go to next step. If no, go to step  2.
  17. Observe the stored information, Capture Info with scan tool. Does 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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