GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Place the heater A/C control or the RECIRC control in the outside air mode.
  2. . Connect a test lamp between B+ and circuit 363 (TAN) at the vacuum/electric solenoid harness connector terminal 4.

Does the test lamp light?

--

Go to Step 2

Go to Step 4

2

Connect a test lamp between B+ and circuit 363 (TAN) at the heater A/C control connector C 2, terminal A 7.

Does the test lamp light?

--

Go to Step 3

Go to Step 5

3

Locate and repair a short to ground on circuit  363 (TAN) between the vacuum/electric solenoid harness connector terminal 4 and the heater A/C control connector C 2, terminal A 7.

Is the repair complete?

--

System OK

--

4

Replace the vacuum/electric solenoid module. Refer to Vacuum Electrical Solenoid Replacement .

Is the repair complete?

--

System OK

--

5

Replace the Heater A/C Control Assembly. Refer to Control Assembly Replacement .

Is the repair complete?

--

System OK

--