GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

    • The condition may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections .
    • Inspect the air delivery system for the following conditions:
       - An obstruction to the airflow
       - Air leaks
       - Misaligned air ducts
       - Broken or binding linkages or doors

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step drives the actuator in both directions. If the actuator door is already in the position you are attempting to drive it to, reverse the polarity to drive the actuator in opposite direction.

Step

Action

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: Air recirculation is inoperative or is always ON.

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn ON the ignition, with the engine OFF.
  2. Place the blower motor switch at the maximum speed position.
  3. Place the mode switch in the vent position.
  4. Place the recirculation switch in the ON position.
  5. Observe the recirculation door.
  6. Place the ambient air switch in the ON position.

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

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Test the recirculation door control A circuit and the recirculation door control B circuit for the following:

    • An open
    • A high resistance
    • A short to ground
    • A short to voltage

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the HVAC control module.
  3. Connect a 10-amp fused jumper wire between the actuator door control A circuit of the Recirculation actuator and battery positive voltage.
  4. Connect a 10-amp fused jumper wire between the actuator door control B circuit of the recirculation actuator and a good ground.
  5. Reverse the polarity between the recirculation actuator control A and B circuits.

Does the actuator shaft rotate in both directions?

Go to Step 5

Go to Step 6

5

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 .

Did you find and correct the condition?

Go to Step 9

Go to Step 8

6

Inspect for poor connections at the harness connector of the recirculation actuator. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 7

7

Important: Perform the recalibration procedure for the Recirculation actuator after replacement.

Replace the recirculation actuator. Refer to Recirculation Actuator Replacement .

Did you complete the replacement?

Go to Step 9

--

8

Replace the HVAC control module. Refer to Control Module References for replacement, setup, and programming.

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