Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS in Wiring Systems.
Automatic Level Control Compressor Motor Always On
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Automatic Level Control Suspension 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 | Is the rear of the vehicle too high? | Go to Step 3 | Go to TESTING FOR INTERMITTENT AND POOR CONNECTIONS in Wiring Systems |
| 3 | Disconnect the air tube from the compressor. Does the rear of the vehicle drop? | Go to Step 4 | Go to Step 6 |
| 4 | Disconnect the compressor motor relay. Does the compressor motor continue to run? | Go to Step 5 | Go to Step 7 |
| 5 | Test the battery positive voltage circuit of the compressor motor for a short to voltage. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems. Did you find and correct the condition? | Go to Step 8 | |
| 6 | Inspect all air tubes for kinked, bent and blockage. Check the exhaust valve for blockage. Did you find and correct the condition? | Go to Step 8 | |
| 7 | Replace the compressor motor relay. Did you complete the replacement? | Go to Step 8 | |
| 8 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
Automatic Level Control Compressor Motor Always On
Automatic Level Control Compressor Motor Inoperative
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Automatic Level Control Suspension 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 | Is the rear of the vehicle low? | Go to Step 3 | Go to TESTING FOR INTERMITTENT AND POOR CONNECTIONS in Wiring Systems |
| 3 | Inspect all air tubes and fittings for leaks. Did you find and correct the condition? | Go to Step 12 | Go to Step 4 |
| 4 | Connect a scan tool. Turn ON the ignition, with the engine OFF. Use the scan tool to turn ON and OFF the compressor motor. Does the compressor turn ON and OFF with each command? | Go to Step 5 | Go to Step 7 |
| 5 | Turn OFF the ignition. Disconnect the compressor motor relay. Probe the battery positive voltage circuit of the compressor relay with a test lamp that is connected to a good ground. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems. Does the test lamp illuminate? | Go to Step 6 | Go to Step 7 |
| 6 | Connect a 20A fused jumper wire between the battery positive voltage circuit of the compressor motor relay and the compressor control circuit of the compressor motor relay. Does the compressor motor turn on? | Go to Step 11 | Go to Step 8 |
| 7 | Test the compressor control circuit of the compressor motor relay for an open, short to ground and high resistance. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 8 |
| 8 | Test the positive battery voltage circuit of the compressor motor for an open and high resistance. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 9 |
| 9 | Test the ground circuit of the compressor motor for an open and high resistance. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 10 |
| 10 | Replace the compressor leveling module. Refer to Air Compressor Replacement . Did you complete the replacement? | Go to Step 12 | |
| 11 | Replace the compressor motor relay. Did you complete the replacement? | Go to Step 12 | |
| 12 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
Automatic Level Control Compressor Motor Inoperative
Air Line Tubing Repair
- Locate the leaking area with soap and water or a stethoscope.
- Cut and remove the leaking line (2) section.
- Remove the plastic retainer pin from one of the nuts.
- Slide the air line tube onto the nut until the line bottoms in the rubber seal (5).
- Hold the air line tube in position. Tighten: Tighten the air line tube repair nut to 8 N.m (70 lb in).
- Install the air line tube to the other end of the coupling.
- Repeat Steps 3 through 5.
- Install the air line tube to the vehicle.
- Inflate the real time damping level control system and inspect for leaks.