Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC C0660 00: Level Control Exhaust CircuitDTC C0660 58: Level Control Exhaust Circuit Incorrect Reaction After Event
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Air Suspension Exhaust Valve Solenoid Control | C0660 00 | C0660 00 | C0660 00 | C0660 58 |
Air Suspension Exhaust Valve Solenoid B+ | C0660 00, C0712 00, C0716 00, C0717 00 | C0660 00 | C0660 00 | C0660 58 |
Leveling Compressor Relay Coil B+ | C0660 00, C0712 00, C0716 00, C0717 00 | -- | -- | -- |
Leveling Compressor Valves B+ | C0660 00, C0712 00, C0716 00, C0717 00 | -- | -- | -- |
Left Rear Suspension Position Sensor Low Reference | -- | -- | C0660 00, C0712 00, C0716 00, C0717 00 | -- |
Right Rear Suspension Position Sensor Low Reference | -- | -- | C0660 00, C0712 00, C0716 00, C0717 00 | -- |
Circuit Description
The air suspension control module (ASCM) controls the compressor relay and exhaust valve ground to maintain the height of the vehicle based on voltage signals from the rear height sensors. The ASCM raises and lowers the vehicle in order to keep the vehicle level.
Conditions for Running the DTC
Battery voltage is between 9-16 volts.
Conditions for Setting the DTC
| • | The exhaust valve control circuit is shorted to voltage, ground, or open when solenoid activation is commanded ON for 2.5 seconds. |
| • | The exhaust valve B+ circuit is shorted to ground or open when solenoid activation is commanded ON for 5 seconds. |
| • | Any component voltage supply circuit from the air suspension control module that is shorted to ground. |
| • | Any suspension position sensor low reference circuit that is shorted to voltage. |
Action Taken When the DTC Sets
| • | The air suspension system will be inoperative. |
| • | The DIC will display SERVICE SUSPENSION SYS. |
Conditions for Clearing the MIL/DTC
| • | DTC C0660 will change from a current DTC to a history DTC on the next ignition cycle. |
| • | DTC C0660 will be cleared from history after 50 ignition cycles. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Air Suspension Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, command the air suspension exhaust solenoid valve ON and OFF with the scan tool. The exhaust solenoid valve should turn ON and OFF with each command.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the air suspension compressor exhaust solenoid.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal and ground.
- Connect a test lamp between the B+ circuit terminal and the control circuit terminal.
- Command the exhaust solenoid ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- If all circuits test normal, replace the air suspension compressor assembly.
| ⇒ | If the test lamp does not illuminate, test for the following conditions listed below. If all circuits test normal, replace the air suspension compressor assembly. |
| • | An open, short to ground, or short to voltage in the air suspension exhaust valve solenoid control circuit |
| • | A short to ground in one of the B+ or 5-volt reference circuits from the air suspension control module |
| • | A short to voltage in one of the position sensor low reference circuits |
| ⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the air suspension control module. |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the air suspension control module. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for air suspension control module replacement, setup and programming |
