GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Suspension Controls Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Did you review the Diagnostic Trouble Code Displaying first?

Go to Step 3

Go to Diagnostic Trouble Code (DTC) Displaying

3

  1. Turn OFF the ignition.
  2. Disconnect the air suspension compressor assembly.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the ground circuit of the air suspension compressor assembly and a battery positive voltage circuit.

Does the test lamp illuminate?

Go to Step 4

Go to Step 7

4

Test the battery positive voltage circuit of the air suspension compressor assembly for an open, short to ground and high resistance. Refer to the following:

    •  Circuit Testing

Did you find and correct the condition?

Go to Step 9

Go to Step 5

5

Test the ignition 3 voltage circuit of the air suspension compressor assembly for an open, short to ground and high resistance. Refer to the following:

    •  Circuit Testing

Did you find and correct the condition?

Go to Step 9

Go to Step 6

6

Inspect for poor connections at the harness connector of the air suspension compressor assembly.

Did you find and correct the condition?

Go to Step 9

Go to Step 8

7

Repair the open in the air suspension compressor assembly ground circuit.

Did you complete the repair?

Go to Step 9

--

8

Replace the air suspension compressor assembly. Refer to Automatic Level Control Air Compressor Replacement .

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 3