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Home >> Chevrolet >> 2001 >> Impala Base, 3.8 K >> Repair and Diagnosis >> External Pages >> Different car >> Section 36 (HVAC Systems - Automatic) >> Self-Diagnostic System >> Diagnostic System Check

Diagnostic System Check

WARNING: This page is about a different car, the 2002 Oldsmobile Intrigue. However, it is still accessible from the selected car via links, so may be relevant.
  1. Did you review DESCRIPTION & OPERATION? If so, go to next step. If not, go to DESCRIPTION & OPERATION  under SELF-DIAGNOSTIC SYSTEM.
  2. Install a scan tool. Does the scan tool power up? If so, go to next step. If not, see SCAN TOOL DOES NOT POWER UP in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
  3. Turn ignition on. Attempt to establish communication with the following control modules:
    • HVAC Control Module
    • Body Control Module
    • Powertrain Control Module
    Does the scan tool communicate with the control modules? If so, go to next step. If not, see SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
    4. NOTE: The engine may start during the following step.
  4. Turn off the engine as soon as you have observed the CRANK POWER mode. Access the Class 2 Power Mode in the Diagnostic Circuit Check on the scan tool. Rotate the ignition switch through all positions while observing the ignition SWITCH POWER mode parameter. Does the ignition switch parameter reading match the ignition switch position for all switch positions? If so, go to next step. If not, see POWER MODE MISMATCH in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
  5. Select the DISPLAY DTCs for HVAC Control Module, BCM and PCM. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, go to appropriate symptom in TROUBLE SHOOTING .
  6. If scan tool displays any DTCs beginning with "U", go to appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT. If scan tool does not display any DTCs beginning with "U", go to next step.
  7. If scan tool displays any DTCs beginning with "B10", go to appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT. If scan tool does not display any DTCs beginning with "B10", go to next step.
  8. If scan tool displays any DTCs beginning with "B" that are related to charging system, go to appropriate STARTING & CHARGING SYSTEMS article in ACCESSORIES & EQUIPMENT. If scan tool does not display any DTCs beginning with "B" related to charging system, go to next step.
  9. If scan tool displays any DTCs related to HVAC system go to DIAGNOSTIC TROUBLE CODE IDENTIFICATION  table. If scan tool does not display any DTCs relating to HVAC system, go to appropriate article in ENGINE PERFORMANCE.
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