GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2004 🢒 Rendezvous - AWD 🢒 Suspension 🢒 Automatic Level Control 🢒 DTC 023

Circuit Description

The height sensor monitors the compressor run time and is limited to 255 seconds for a leveling function.

Conditions for Running the DTC

Ignition On.

Conditions for Setting the DTC

This DTC is set when the height sensor detects the compressor has been running for 255 seconds during a leveling function.

Action Taken When the DTC Sets
    • The height sensor disables the leveling functions.
    • The height sensor disables inflator functions.

Conditions for Clearing the DTC

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

Diagnostic Aids

An AIR LEAK in the system will cause this DTC to set.

Test Description

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

  1. Tests for battery positive voltage at the compressor relay. The ELC fuse supplies power to the compressor relay.

    2.

  2. Verifies that the compressor relay contacts are working.

    3.

  3. Tests the ground circuit for the compressor motor.

    4.

  4. Verifies that the compressor relay is replaced.

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. Check all air lines and exhaust solenoid valve for air leakage.
  2. Check both rear shock absorbers for air leakage.

Did you find and correct the condition?

Go to Step 11

Go to Step 3

3

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

Does the test lamp illuminate?

Go to Step 4

Go to Step 8

4

  1. Connect a test lamp between the battery positive output circuit of the compressor relay and the compressor motor ground circuit.
  2. With the accessory inflator switch, command the accessory inflator solenoid ON and OFF .

Does the test lamp turn ON and OFF with each command?

Go to Step 6

Go to Step 5

5

Test the ground circuit of the compressor motor for a open. Refer to Circuit Testing 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 compressor motor. 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 compressor relay. 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 of the compressor relay coil. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 11

--

9

Replace the compressor motor. Refer to Air Compressor Replacement .

Did you complete the replacement?

Go to Step 11

--

10

Replace the compressor relay. Refer to Automatic Level Control Relay 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