For 1990-2009 cars

### Diagnostic Aids

• | The condition may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

• | Inspect the air delivery system for the following conditions:

• | A dirty HVAC air filter

• | An obstruction to the airflow

• | Air leaks

• | Misaligned air ducts

• | Broken or binding linkages or doors

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views
1 | Did you perform the HVAC Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - HVAC Systems - Automatic
2 |

1. Turn ON the ignition, with the engine OFF.
2. Turn OFF the HVAC control module.

Is the blower motor OFF?

Go to Step 3

Go to Blower Motor Always On

3 | Place the blower motor switch in each speed position. Does the blower motor operate in any of the speed positions? | Go to Step 4 | Go to Blower Motor Inoperative
4 | Does the blower motor operate in each speed position? | Go to Step 5 | Go to Blower Motor Malfunction
5 |

1. Place the blower motor switch in the maximum speed position.
2. Place the mode switch in the bi-level position.
3. Place the recirculation switch in the ON position.
4. Observe the drive shaft of the recirculation actuator.
5. Place the recirculation switch in the OFF position.

Does the recirculation door move from the recirculation position to the outside air position?

Go to Step 6

Go to Air Recirculation Malfunction

6 |

1. Place the mode switch in the PANEL position.
2. Observe the drive shaft of the mode actuator.
3. Place the defrost switch in the ON position.

Does the drive shaft of the mode actuator rotate?

Go to Diagnostic Aids

Go to Step 7

7 | Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 8
8 | Replace the HVAC control module. Refer to HVAC Control Module Replacement . Did you complete the replacement? | Go to Step 9 | --
9 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2