GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The exhaust accumulator will detect conditions of excessive exhaust solenoid valve activity. Usually this condition is generally due to the presence of pneumatic line blockages or unloaded vehicle conditions.

Conditions for Setting the DTC

If the exhaust valve is active for more than 5 minutes and the rear of the vehicle remains above a trim position.

Action Taken When the DTC Sets

    • All exhaust function activity is disabled.
    • The LEVELING indicator lamp flashes.

Conditions for Clearing the DTC

    • The DTC will clear when no error is detected and the cause for the error has been repaired.
    • Using a scan tool.

Diagnostic Aids

Refer to the diagnostic table.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Checks the automatic level control sensor lick-rod for defects.

  2. Checks air compressor intake filter function.

  3. Checks tubing for blockages.

DTC 11 Exhaust Accumulator Malfunction

Step

Action

Value(s)

Yes

No

1

Was the system leak test been performed?

--

Go to Step 2

Go to ALC Suspension System Check .

2

Inspect the link-rod and ALC sensor arm for abnormalities. Refer to Automatic Level Control in Suspension.

Were any abnormalities found?

--

Go to Step 8

Go to Step 3

3

  1. Disconnect the air compressor intake filter from the rear suspension leveling air compressor.
  2. Disconnect the automatic level control sensor connector.
  3. Connect a 3A fused jumper wire between terminal C of the sensor connector and a known good ground.

Is the air exiting the intake filter port?

--

Go to Step 4

Go to Step 5

4

Inspect the filter and tubing for a blockage. If a blockage is found, replace the filter and tubing. Refer to Automatic Level Control Air Compressor Air Filter Replacement .

Is the replacement complete?

--

Go to Step 9

--

5

  1. Disconnect the jumper wire from the sensor connector.
  2. Disconnect the tubing from the air dryer.

Is air exiting the tubing?

--

Go to Step 7

Go to Step 6

6

Replace the tubing between both rear shock absorbers.

Refer to Air Tube Replacement .

Is the replacement complete?

--

Go to Step 9

--

7

Replace the rear suspension leveling air compressor. Refer to Air Compressor Replacement .

Is the replacement complete?

--

Go to Step 9

--

8

  1. Turn OFF the ignition switch
  2. Replace the sensor. Refer to Automatic Level Control Sensor Replacement .

Is the replacement complete?

--

Go to Step 9

--

9

  1. Clear any DTC.
  2. Connect all of the connectors that were disconnected.
  3. Reinstall components that were removed.
  4. Wait for at least 5 minutes.
  5. Turn the ignition switch to the ON position.

Is the LEVELING indicator lamp flashing?

--

Go to Step 1

System OK