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Test I: Too Cold In Vehicle

WARNING: This page is about a different car, the 2002 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: For correct circuit identification and connector terminal locations, see CONNECTOR IDENTIFICATION  and/or WIRING DIAGRAMS .
NOTE: Definition: The temperature cannot be adjusted, or the heating is insufficient.
  1. Perform DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Turn ignition on, engine off. Place blower control 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, go to TEST D: BLOWER MOTOR INOPERATIVE .
  3. If blower motor operates in desired speed, go to next step. If blower motor does not operate in desired speed, go to TEST E: BLOWER MOTOR MALFUNCTION .
  4. Place mode switch in VENT position. Place blower motor switch in maximum speed position. Place outside air switch in ON position. Place recirculation switch in ON position. If recirculation door moves from recirculation position to outside air position, go to next step. If recirculation door does not move from recirculation position to outside air position, go to TEST B: AIR RECIRCULATION MALFUNCTION .
  5. Inspect cooling system for low coolant level, loose or worn accessory drive belt, leaking or kinked radiator or heater hoses, missing radiator filler cap pressure seal or leaking radiator cap. Repair as necessary, then go to step  18. If cooling system is okay, go to next step.
  6. Start engine. Place mode switch in OFF or HEAT position. If A/C compressor operates, go to TEST F: COMPRESSOR CLUTCH DOES NOT DISENGAGE . If A/C compressor does not operate, go to next step.
  7. Turn ignition on, engine off. Observe air temperature actuator drive shaft. Place air temperature switch from coldest position to warmest position. If air temperature actuator drive shaft rotates at all, go to next step. If air temperature actuator drive shaft does not rotate at all, go to step  9.
  8. Inspect air temperature door and air temperature actuator for misaligned actuator, broken or binding linkages or air temperature door, obstructions, or missing/misaligned seals. Repair as necessary, then go to step  18. If no problem was found, go to next step.
  9. Test air temperature actuator ignition "3" voltage circuit for an open or a high resistance. Repair as necessary, then go to step  18. If circuit is okay, go to next step.
  10. Test air temperature actuator ground circuit for an open. Repair as necessary, then go to step  18. If circuit is okay, go to next step.
  11. Test air temperature actuator door position signal circuit for an open, high resistance, short to ground, or short to voltage. Repair as necessary, then go to step  18. If circuit is okay, go to next step.
    12. NOTE: Ensure HVAC control assembly connector is connected during this step to avoid misdiagnosis.
  12. Turn ignition on, engine off. Measure voltage from air temperature actuator door position signal circuit to ground. Place air temperature switch from coldest position to warmest position. If voltage measures 0-12 volts with a smooth transition between COLD and HOT, go to step  15. If voltage does not measure 0-12 volts with a smooth transition between COLD and HOT, go to next step.
  13. Inspect for poor connections at air temperature actuator harness connector. Repair as necessary, then go to step  18. If connections are okay, go to next step.
  14. Inspect air temperature actuator, door and any attaching linkage for binding or a condition that prevents drive shaft rotation. Repair as necessary, then go to step  18. If no problem was found, go to step  16.
  15. Inspect for poor connections at HVAC control assembly harness connector. Repair as necessary, then go to step  18. If connections are okay, go to step  17.
  16. Replace air temperature actuator. See AIR TEMPERATURE ACTUATOR  under REMOVAL & INSTALLATION. After replacement, go to step  18.
  17. Replace HVAC control assembly. See HVAC CONTROL ASSEMBLY  under REMOVAL & INSTALLATION. After replacement, go to next step.
  18. Operate system to verify repair. If system operates properly, system is okay. If system does not operate properly, go to step  2.
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