GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you review the Control Assembly Description and perform the necessary inspections?

--

Go to Step 2

Go to Symptoms

2

Inspect the A/C Cruise fuse in the fuse block.

Is the A/C Cruise fuse open?

--

Go to Step 3

Go to Step 4

3

Locate and repair a short to ground in the Battery supply circuit to the A/C Control and Temperature Control Actuator Motor. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 6

--

4

A fault has occurred in the vacuum selector, the vacuum source, the vacuum actuators, the vacuum hoses to actuators, the linkage from actuators to values, or faulty valves. Refer to Vacuum System for further diagnosis.

Is the action complete?

--

Go to Step 6

Go to Step 5

5

Replace the HVAC Control assembly. Refer to Control Assembly Replacement .

Is the repair complete?

--

Go to Step 6

--

6

Verify that the system operates properly .

Does the system operate properly ?

--

System OK

Go to Symptoms