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Suspension Control System - Suspension Leveling: Overview Chevrolet Uplander I

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: This step tests for voltage at the coil side of the accessory inflator valve. The ELC relay fuse supplies power to the coil side of the accessory inflator valve.
  2. 3: This step verifies that the height sensor is providing ground to the accessory inflator valve.
  3. 4: This step tests if ground is constantly being applied to the accessory inflator valve.
  4. 9: This step verifies that the automatic level control sensor is self tested after replacement.
StepActionYesNo
Schematic Reference: Automatic Level Control Suspension Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Turn ON the ignition. Disconnect the accessory inflator valve. Probe the battery positive voltage circuit of the accessory inflator valve with a test lamp that is connected to a good ground. Does the test lamp illuminate?Go to Step 3Go to Step 7
3Connect a test lamp between the control circuit of the accessory inflator valve and the battery positive voltage circuit of the accessory inflator valve. With the accessory inflator switch, command the accessory inflator valve ON and OFF. Does the test lamp turn ON and OFF with each command?Go to Step 5Go to Step 4
4Test the control circuit of the accessory inflator valve for the following conditions: A ground An open Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 10Go to Step 6
5Inspect for poor connections at the accessory inflator valve. 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 10Go to Step 8
6Inspect 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 10Go to Step 9
7Repair the battery positive voltage circuit of the accessory inflator valve. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 10
8Replace the accessory inflator valve. Refer to Inflator Solenoid Replacement . Did you complete the replacement?Go to Step 10
9IMPORTANT: System untested code will continue to flash until Self test has been completed after automatic level control sensor replacement. Replace the automatic level control sensor. Refer to Automatic Level Control Sensor Replacement .Did you complete the replacement?Go to Step 10
10Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 2System OK
IMPORTANT
System untested code will continue to flash until Self test has been completed after automatic level control sensor replacement.

DTC 011

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: This step tests for mechanical damage to automatic level control sensor link.
  2. 3: Automatic level control sensor replacement.
StepActionYesNo
Schematic Reference: Automatic Level Control Suspension Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Inspect the automatic level control sensor link for damage or being disconnected. Did you find and correct the condition?Go to Step 4Go to Step 3
3Replace the automatic level control sensor. Refer to Automatic Level Control Sensor Replacement . Did you complete the replacement?Go to Step 4
4Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 2System OK

DTC 013

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: This step tests for short to ground in compressor relay control circuit.
  2. 3: This step verifies that the automatic level control sensor is self tested after replacement.
StepActionYesNo
Schematic Reference: Automatic Level Control Suspension Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Test the control circuit of the compressor relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 7Go to Step 3
3IMPORTANT: System untested codes will continue to flash until the self test has been completed after automatic level control sensor replacement. Replace the automatic level control sensor. Refer to Automatic Level Control Sensor Replacement .Did you complete the replacement?Go to Step 4
4Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 2System OK
IMPORTANT
System untested codes will continue to flash until the self test has been completed after automatic level control sensor replacement.

DTC 021

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: This step tests for battery positive voltage at the relay coil. The ELC fuse supplies power to the relay coil of the level control compressor relay.
  2. 3: This step verifies that the automatic level control sensor is providing ground to the level control compressor relay.
  3. 4: This step tests if battery positive voltage is constantly being applied to the level control compressor relay control circuit or the circuit is open.
  4. 9: This step verifies that the automatic level control sensor is self tested after replacement.
StepActionYesNo
Schematic Reference: Automatic Level Control Suspension Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Turn ON the ignition. Disconnect the level control compressor relay. Probe the battery positive voltage circuit of the level control compressor relay with a test lamp that is connected to a good ground. Does the test lamp illuminate?Go to Step 3Go to Step 7
3Connect a test lamp between the coil control circuit of the level control compressor relay and the battery positive voltage circuit of the level control compressor relay. With the accessory inflator switch, command the accessory inflator valve ON and OFF. Does the test lamp turn ON and OFF with each command?Go to Step 5Go to Step 4
4Test the control circuit of the level control compressor relay for a short to voltage, ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 10Go to Step 6
5Inspect for poor connections at the level control 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 10Go to Step 8
6Inspect for poor connections at the harness connector of the automatic level control 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 10Go to Step 9
7Repair the battery positive voltage circuit of the level control compressor relay coil. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 10
8Replace the level control compressor relay. Refer to Automatic Level Control Relay Replacement . Did you complete the replacement?Go to Step 10
9IMPORTANT: System untested codes will continue to flash until self test has been completed after automatic level control sensor replacement. Replace the automatic level control sensor. Refer to Automatic Level Control Sensor Replacement .Did you complete the replacement?Go to Step 10
10Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 2System OK
IMPORTANT
System untested codes will continue to flash until self test has been completed after automatic level control sensor replacement.

DTC 022

The numbers below refer to the step numbers on the diagnostic table.

  1. 3: This step tests for battery positive voltage at the level control compressor relay. The ELC fuse supplies power to the level control compressor relay.
  2. 4: This step verifies that the level control compressor relay contacts are working.
  3. 5: This step tests the ground circuit for the compressor motor.
  4. 10: This step verifies that the level control compressor relay is replaced.
StepActionYesNo
Schematic Reference: Automatic Level Control Suspension Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Check all air lines and exhaust valves for air leakage. Check both rear shock absorbers for air leakage. Did you find and correct the condition?Go to Step 11Go to Step 3
3Turn ON the ignition. Disconnect the level control compressor relay. Probe the battery positive voltage circuit of the level control compressor relay with a test lamp that is connected to a good ground. Does the test lamp illuminate?Go to Step 4Go to Step 8
4Connect a test lamp between the battery positive output circuit of the level control compressor relay and the compressor motor ground circuit. With the accessory inflator switch, command the accessory inflator valve ON and OFF. Does the test lamp turn ON and OFF with each command?Go to Step 6Go to Step 5
5Test 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 11Go to Step 7
6Inspect 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 11Go to Step 9
7Inspect for poor connections at the harness connector of the level control 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 11Go to Step 10
8Repair the battery positive voltage circuit of the level control compressor relay coil. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 11
9Replace the compressor motor. Refer to Air Compressor Replacement . Did you complete the replacement?Go to Step 11
10Replace the level control compressor relay. Refer to Automatic Level Control Relay Replacement . Did you complete the replacement?Go to Step 11
11Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 2System OK

DTC 023

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: This step tests for voltage at the coil side of the exhaust valve. The ELC fuse supplies power to the coil side of the exhaust valve.
  2. 3: This step verifies that the automatic level control sensor is providing ground to the exhaust valve.
  3. 4: This step tests if ground is constantly being applied to the exhaust valve.
  4. 9: This step verifies that the automatic level control sensor is self tested after replacement.
StepActionYesNo
Schematic Reference: Automatic Level Control Suspension Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Turn ON the ignition. Disconnect the exhaust valve. Probe the battery positive voltage circuit of the exhaust valve with a test lamp that is connected to a good ground. Does the test lamp illuminate?Go to Step 3Go to Step 7
3Connect a test lamp between the control circuit of the exhaust valve and the battery positive voltage circuit of the exhaust valve. Does the test lamp illuminate?Go to Step 4Go to Step 5
4Test the control circuit of the exhaust valve for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 10Go to Step 6
5Inspect for poor connections at the exhaust valve. 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 10Go to Step 8
6Inspect for poor connections at the harness connector of the automatic level control 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 10Go to Step 9
7Repair the battery positive voltage circuit of the exhaust valve. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 10
8Replace the exhaust valve. Refer to Air Compressor Replacement . Did you complete the replacement?Go to Step 10
9IMPORTANT: System untested codes will continue to flash until self test has been completed after automatic level control sensor replacement. Replace the automatic level control sensor. Refer to Automatic Level Control Sensor Replacement .Did you complete the replacement?Go to Step 10
10Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 2System OK
IMPORTANT
System untested codes will continue to flash until self test has been completed after automatic level control sensor replacement.

DTC 031

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: This step tests for voltage at the coil side of the exhaust valve. The ELC fuse supplies power to the coil side of the exhaust valve.
  2. 3: This step verifies that the automatic level control sensor is providing ground to the exhaust valve.
  3. 4: This step tests if ground is constantly being applied to the exhaust valve.
  4. 10: This step verifies that the automatic level control sensor is self tested after replacement.
StepActionYesNo
Schematic Reference: Automatic Level Control Suspension Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Turn ON the ignition. Disconnect the exhaust valve. Probe the battery positive voltage circuit of the exhaust valve with a test lamp that is connected to a good ground. Does the test lamp illuminate?Go to Step 3Go to Step 8
3Connect a test lamp between the control circuit of the exhaust valve and a good ground. Does the test lamp illuminate?Go to Step 4Go to Step 5
4Test the control circuit of the exhaust valve 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 11Go to Step 6
5Test the control circuit of the exhaust valve 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 11Go to Step 7
6Inspect for poor connections at the exhaust valve. 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 11Go to Step 9
7Inspect for poor connections at the harness connector of the automatic level control 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 11Go to Step 10
8Repair the battery positive voltage circuit to the exhaust valve. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 11
9Replace the exhaust valve. Refer to Air Compressor Replacement . Did you complete the replacement?Go to Step 11
10IMPORTANT: System untested codes will continue to flash until self test has been completed after automatic level control sensor replacement. Replace the automatic level control sensor. Refer to Automatic Level Control Sensor Replacement .Did you complete the replacement?Go to Step 11
11Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 2System OK
IMPORTANT
System untested codes will continue to flash until self test has been completed after automatic level control sensor replacement.

DTC 032

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: This step tests for something mechanical that is not allowing the vehicle to lower.
  2. 3: This step verifies the automatic level control sensor connector to have a good connection.
StepActionYesNo
Schematic Reference: Automatic Level Control Suspension Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Check all air lines and exhaust valves for airflow blockage. Check both rear shock absorbers for binding. Did you find and correct the condition?Go to Step 5Go to Step 3
3Inspect for poor connections at the harness connector of the automatic level control 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 5Go to Step 4
4IMPORTANT: System untested codes will continue to flash until a self test has been completed after automatic level control sensor replacement. Replace the automatic level control sensor. Refer to Automatic Level Control Sensor Replacement .Did you complete the replacement?Go to Step 5
5Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 2System OK
IMPORTANT
System untested codes will continue to flash until a self test has been completed after automatic level control sensor replacement.

DTC 033

Symptoms - Automatic Level Control

Review the system operation in order to familiarize yourself with the system functions. Refer to Automatic Level Control Description and Operation .

Before diagnosing any Automatic Level Control (ALC) System symptoms, perform the ALC self-test. The ALC self-test will test the system operation and display any current fault codes. Refer to Diagnostic Trouble Code (DTC) Displaying for instructions on activating the self-test and displaying fault codes.