GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The LEVELING indicator lamp is activated by the Automatic Level Control (ALC) sensor whenever a compress cycle is requested. The sensor provides a switched path to ground. The sensor will flash the lamp when certain DTCs are detected.

Conditions for Setting the DTC

The DTC will set when the sensor detects that the lamp output is not externally pulled up to B+ when the sensor output is not active and the ignition signal is high.

Action Taken When the DTC Sets

    • The sensor's discrete low side output drive for the lamp is disabled.
    • The sensor continuously attempts to recover from the fault.
    • DTC 08 is stored as a history code at the end of the ignition cycle.

Conditions for Clearing the DTC

    • The DTC will clear when B+ is present at the low side output drive.
    • Using a scan tool.

Diagnostic Aids

    • Check the integrity of the LEVELING indicator lamp bulb.
    • Refer to the diagnostic table.

Test Description

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

  1. Checks for a short to ground in circuits

  2. Checks for an open in circuits XY1 or XY2.

DTC 08 Level Control Indicator Short to Ground

Step

Action

Value(s)

Yes

No

1

Was the Automatic Level Control (ALC) System Check performed?

--

Go to Step 2

Go to ALC Suspension System Check .

2

  1. Disconnect the ALC sensor connector.
  2. Turn the ignition switch to the ON position.

Is the LEVELING indicator lamp illuminated?

--

Go to Step 3

Go to Step 4

3

Locate and repair a short to ground in circuits XY1 and/or XY2.

Is the repair complete?

--

Go to Step 7

--

4

Connect a 3A fused jumper wire between terminal G of the sensor connector and a known good ground.

Is the LEVELING indicator lamp illuminated?

--

Go to Step 6

Go to Step 5

5

Locate and repair an open in circuits XY1 and/or XY2.

Is the repair complete?

--

Go to Step 7

--

6

Replace the ALC sensor. Refer to Automatic Level Control Sensor Replacement .

Is the replacement complete?

Go to Step 7

--

7

  1. Turn the ignition switch to the OFF position.
  2. Connect all of the connectors that were disconnected.
  3. Reinstall all of the components that were removed.
  4. Turn the ignition switch to the ON position.
  5. Wait for at least 15 seconds. Check the operation of the LEVELING indicator lamp.

Does the LEVELING indicator lamp operate properly?

--

System OK

Go to Step 1