GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The height sensor monitors the exhaust solenoid control circuity for a short to battery positive voltage or an open circuit.

Conditions for Running the DTC

Ignition On.

Conditions for Setting the DTC

This DTC is set when the height sensor detects the exhaust solenoid control circuit is shorted to battery positive voltage or an open circuit.

Action Taken When the DTC Sets

The height sensor disables leveling functions.

Conditions for Clearing the DTC

The conditions that caused the DTC to set have been removed.

Ignition switch has cycled from off to on.

Diagnostic Aids

A short to battery positive voltage or an open circuit in the exhaust solenoid control circuit will set this DTC.

Test Description

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

  1. Tests for voltage at the coil side of the exhaust solenoid. The ELC fuse supplies power to the coil side of the exhaust solenoid.

  2. Verifies that the height sensor is providing ground to the exhaust solenoid.

  3. Tests if ground is constantly being applied to the exhaust solenoid.

  4. Verifies that the sensor is self tested after replacement.

Step

Action

Yes

No

Schematic Reference: Automatic Level Control Schematics

1

Did you perform the Automatic Level Control Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Automatic Level Control

2

  1. Turn ON the ignition.
  2. Disconnect the exhaust solenoid.
  3. Probe the battery positive voltage circuit of the exhaust solenoid with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 3

Go to Step 8

3

Connect a test lamp between the control circuit of the exhaust solenoid and a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 5

4

Test the control circuit of the exhaust solenoid for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 6

5

Test the control circuit of the exhaust solenoid for an open circuit. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 7

6

Inspect for poor connections at the exhaust solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.

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 height sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 10

8

Repair the battery positive voltage circuit to the exhaust solenoid. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 11

--

9

Replace the exhaust solenoid. Refer to Air Compressor Replacement .

Did you complete the replacement?

Go to Step 11

--

10

Important: System untested code will continue to flash until self test has been completed after sensor replacement .

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

Did you complete the replacement?

Go to Step 11

--

11

Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK