GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The left air suspension sensor arm is attached to an armature that rotates inside a coil. The air suspension compressor assembly determines the angle of the sensor arm by measuring the inductive voltage of the left air suspension sensor signal at 50 ms intervals via the left air suspension sensor signal circuit.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The air suspension compressor assembly detects a invalid height sensor signal.

Action Taken When the DTC Sets

    • The air suspension compressor assembly shall disregard the left Air Suspension Sensor input and use the right Air Suspension Sensor to determine the vehicle height.
    • If both Air Suspension Sensor DTCs are set, the Air Suspension Compressor Assembly shall deactivate the compressor, corner solenoids and exhaust solenoids. All leveling functions will be disabled. Inflator functions will not be disabled.

Conditions for Clearing the DTC

The DTC will automatically clear when the condition for setting the DTC is removed.

Diagnostic Aids

Resistance of the Air Suspension Sensor at room temperature and normal vehicle height is approximately 87 ohms. The resistance range of the sensor is 75-100 ohms.

Step

Action

Value(s)

Yes

No

Schematic Reference: Suspension Controls Schematics

1

Did you perform the Air Suspension Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Air Suspension

2

Verify the fault is present.

Does the system operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the harness connector of the left air suspension sensor.
  3. Disconnect the harness connector of the air suspension compressor assembly.
  4. Test the air suspension sensor signal circuit for an open, short to voltage and a short to ground. Refer to Testing for Continuity , Testing for a Short to Voltage and Testing for Short to Ground in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 4

4

Test the air suspension return circuit for an open, short to voltage and a short to ground. Refer to Testing for Continuity , Testing for a Short to Voltage and Testing for Short to Ground in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 5

5

Measure the resistance of the air suspension sensor.

Does the resistance measure within the specified value?

75-100 Ohms

Go to Step 6

Go to Step 9

6

Inspect for poor connections at the harness connector of the left air suspension sensor.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 7

7

Inspect for poor connections at the harness connector of the Air Suspension Compressor Assembly.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 8

8

Replace the air suspension compressor assembly.

Refer to Automatic Level Control Air Compressor Replacement

Did you complete the replacement?

--

Go to Step 10

--

9

Replace the left air suspension sensor.

Refer to Air Spring Leveling Sensor Replacement

Did you complete the replacement?

--

Go to Step 10

--

10

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3