GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Air Suspension 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 inflator switch at air suspension compressor assembly.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the inflater switch 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 6

4

Connect a 3-amp fused jumper wire between the control circuit of the air suspension compressor assembly and the ground circuit of the air suspension compressor assembly.

Does the compressor start and run?

Go to Step 7

Go to Step 5

5

Test the control circuit of the air suspension inflator switch for an open, short to ground, short to voltage and high resistance. Refer to the following:

    •  Circuit Testing

Did you find and correct the condition?

Go to Step 11

Go to Step 8

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 11

Go to Step 9

7

Inspect for poor connections at the harness connector of the air suspension inflator switch.

Did you find and correct the condition?

Go to Step 11

Go to Step 10

8

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

Did you find and correct the condition?

Go to Step 11

Go to Step 9

9

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

Did you complete the replacement?

Go to Step 11

--

10

Replace the air suspension inflator switch. Refer to Inflator Air Switch Replacement .

Did you complete the replacement?

Go to Step 11

--

11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 1