GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Turn the ignition switch to the RUN position.
  2. Disconnect the connector at the temperature actuator.
  3. Connect a J 39200 Digital Multimeter (DMM) between the temperature actuator connector cavity 8 and ground.
  4. Adjust the temperature control on the HVAC control module while observing the response.

Is a smooth variable voltage observed?

--

Go to Step 9

Go to Step 2

2

  1. Disconnect connector C2 on the HVAC control module.
  2. Connect a test lamp between the HVAC control module connector C2 cavity B and ground.

Does the test lamp light?

--

Go to Step 3

Go to Step 4

3

Repair the short to voltage on CKT 733 (LT BLU), between the HVAC control module and the temperature actuator.

Is the repair complete?

--

System OK

--

4

Connect a self-powered test lamp between the HVAC control module connector C2 cavity B and ground.

Does the test lamp light?

--

Go to Step 5

Go to Step 6

5

Repair the short to ground on CKT 733 (LT BLU), between the HVAC control module and the temperature actuator

Is the repair complete?

--

System OK

--

6

Connect a self-powered test lamp between the HVAC control module connector C2 cavity B and the temperature actuator connector cavity 8.

Does the test lamp light?

--

Go to Step 7

Go to Step 8

7

Replace the HVAC control module.

Is the repair complete?

--

System OK

--

8

Repair the open on CKT 733 (LT BLU), between the HVAC control module and the temperature actuator.

Is the repair complete?

--

System OK

--

9

Connect a test lamp between the temperature actuator connector cavity 10 and ground.

Does the test lamp light?

--

Go to Step 11

Go to Step 10

10

Repair the open in CKT 141 (BRN), between S268 and the temperature actuator.

Is the repair complete?

--

System OK

--

11

Connect a self-powered test lamp between the temperature actuator connector cavity 7 and ground.

Does the test lamp light?

--

Go to Step 12

Go to Step 13

12

Replace the temperature actuator.

Is the repair complete?

--

System OK

--

13

Repair the open in CKT 150 (BLK), between the temperature actuator and S244.

Is the repair complete?

--

System OK

--