GM Service Manual Online
For 1990-2009 cars only

Test Description

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

  1. To observe the recirculation door actuator, lower the glove box door off of the upper attachments.

  2. This step tests the HVAC control module's ability to reverse the polarity of the door control A and door control B circuits. The test lamp should illuminate.

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 HVAC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Manual

2

  1. Turn ON the ignition, with the engine OFF.
  2. Place the blower motor switch to the low 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 recirculation switch in the OFF position.

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

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the recirculation actuator.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the recirculation door control A circuit and the recirculation door control B circuit of the recirculation actuator.
  5. Place the recirculation switch in the ON position.

Does the test lamp illuminate?

Go to Step 5

Go to Step 4

4

Connect a test lamp between the recirculation door control B circuit of the recirculation actuator and a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 8

5

Place the recirculation switch in the OFF position.

Does the test light illuminate?

Go to Step 6

Go to Step 10

6

Inspect the recirculation door and the recirculation actuator for the following conditions:

    • A misaligned recirculation actuator
        Refer to Recirculation Actuator Replacement .
    • Broken or binding linkages or recirculation door
    • An obstruction that prevents the recirculation actuator from operating within the full range of motion
    • Missing seals to the recirculation door
    • Misaligned seals to the recirculation door

Did you find and correct the condition?

Go to Step 13

Go to Step 9

7

Test the recirculation door control A circuit of the HVAC control module for a short to ground, short to voltage, an open and for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 10

8

Test the recirculation door control B circuit of the HVAC control module for a short to ground, short to voltage, an open and for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 10

9

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

Did you find and correct the condition?

Go to Step 13

Go to Step 11

10

Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 12

11

Replace the recirculation actuator. Refer to Recirculation Actuator Replacement .

Did you complete the replacement?

Go to Step 13

--

12

Replace the HVAC control module. Refer to HVAC Control Module Replacement .

Did you complete the replacement?

Go to Step 13

--

13

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3