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Test I: Too Hot In Vehicle

WARNING: This page is about a different car, the 2002 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: For circuit reference, see CONNECTOR IDENTIFICATION  and/or WIRING DIAGRAMS  .
NOTE: Definition: The temperature cannot be adjusted, or cooling is insufficient during A/C operation.
  1. If diagnostic system check was not performed, go to DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. If diagnostic system check was performed, go to next step.
    2. NOTE: Both left driver and right passenger, air temperature control concerns are diagnosed in this test.
  2. Turn ignition on. Place blower motor switch in each speed position. If blower motor operates in any speed position, go to next step. If blower motor does not operate in any speed position, see TEST C: BLOWER MOTOR INOPERATIVE .
  3. If blower motor operates in desired speeds, go to next step. If blower motor does not operate in desired speeds, see TEST D: BLOWER MOTOR MALFUNCTION .
  4. Start engine. Place blower motor switch in maximum speed position. Place mode switch in MAX position. If recirculation door moves to recirculation position, go to next step. If recirculation door does not move to recirculation position, see VACUUM CONTROL SYSTEM  under SYSTEM TESTS.
  5. If vehicle is too hot when A/C system is on, go to next step. If vehicle is not too hot when A/C system is on, go to step  8.
    6. NOTE: Ambient air temperature must be above 38°F (3°C).
  6. Place blower motor switch in maximum speed position. Place mode switch in VENT position. Place temperature switch in coldest position. Turn A/C on. If A/C compressor operates, go to next step. If A/C compressor does not operate, see TEST F: COMPRESSOR CLUTCH DOES NOT ENGAGE .
  7. Perform refrigerant system performance test. See A/C SYSTEM PERFORMANCE TEST  under PERFORMANCE TESTS. If condition is found and corrected, go to step  21. If condition is not found go to next step.
  8. Place headlamp switch ON. Place dimmer switch in brightest position. Observe left and right temperature actuator drive shafts. If left and right temperature actuator drive shafts rotate, go to next step. If left and right temperature actuator drive shafts do not rotate, go to step  10.
  9. Inspect air temperature door and air temperature actuator for misalignment, broken or binding linkages, an obstruction that prevents air temperature door from operating within its full range of motion, missing or misaligned seals of air temperature door. If any condition described is found, repair as necessary. When repair is complete, go to step  21. If any condition described is not found, go to next step.
  10. Check suspect air temperature actuator ignition 3 voltage circuit for an open or high resistance. See WIRING DIAGRAMS . If an open or high resistance is found, repair as necessary. When repair is complete, go to step  21. If short to ground or high resistance is not found, go to next step.
  11. Check suspect air temperature actuator ground circuit for an open. See WIRING DIAGRAMS . If an open is found, repair as necessary. When repair is complete, go to step  21. If an open condition is not found, go to next step.
  12. Check suspect air temperature door control circuit of air temperature actuator for short to voltage, short to ground, open or high resistance. See WIRING DIAGRAMS . If short to voltage, short to ground, open or high resistance is found, repair as necessary. When repair is complete, go to step  21. If short to voltage, short to ground, open or high resistance is not found, go to next step.
  13. Check ignition 3 voltage circuit of HVAC control assembly for an open, high resistance, or a short to ground. If condition was found and corrected, go to step  21. If condition was not found, go to next step.
  14. Check ground circuit of HVAC control assembly for an open or a high resistance. If condition was found and corrected, go to step  21. If condition was not found, go to next step.
  15. Ensure HVAC control assembly connector is connected. Turn ignition on, engine off. Using a DVOM connected to ground, measure suspect actuator door control circuit voltage. See WIRING DIAGRAMS . Place air temperature switch from coldest to warmest position. If measured voltage is between zero-12 volts with a smooth transition between COLD and HOT, go to next step. If measured voltage is not between zero-12 volts with a smooth transition between COLD and HOT, go to step  18.
  16. Check suspect air temperature sensor harness connector for poor connections. If poor connection is found, repair as necessary. When repair is complete, go to step  21. If poor connection is not found, go to step  19.
  17. Inspect air temperature actuator, door and any attaching linkage for binding or a condition that prevents drive shaft rotation. If condition was found and corrected, go to step  21. If condition was not found, go to next step.
  18. Check HVAC control assembly harness connector for poor connections. If poor connection is found, repair as necessary. When repair is complete, go to step  21. If poor connection is not found, go to step  20.
  19. Replace suspect air temperature actuator. See ACTUATORS  under REMOVAL & INSTALLATION. When repairs are complete, go to step  21.
  20. Replace HVAC control assembly. See HVAC CONTROL ASSEMBLY  under REMOVAL & INSTALLATION. When repairs are complete, go to step.
  21. Operate system to verify repair. If condition is corrected, system is okay. If condition is not corrected, go to step  3.
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