C0712

DTC C0712 (Symptom 01)

Circuit Description
The automatic level control (ALC) adjusts the vehicle suspension ride height. The electronic suspension control (ESC) module determines the height of the vehicle based on the voltage from the ALC sensor. The ESC module grounds the ELC COMP relay and the exhaust control solenoid to raise and lower the vehicle in order to keep the vehicle level.

DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C0712.01 Level Control Compressor Circuit High

Conditions for Running the DTC
^ The ESC module is powered up.
^ The ESC module is commanding the compressor ON.

Conditions for Setting the DTC
The compressor relay output is found to be shorted to battery for 10 seconds.

Action Taken When the DTC Sets
The ALC will be inoperative.

Conditions for Clearing the MIL/DTC
The ESC module does not detect a failure during the self test.

Diagnostic Aids
^ Inspect all wiring harnesses carefully for chaffs and proper routing.
^ This circuit is monitored during every functional operation of the compressor relay output and every 3.3 milliseconds when output is active. If a compressor relay fault is detected, the ESC module retries the output every 15 seconds to try to recover form the fault.

Test Description

Step 1 - Step 13:

The numbers below refer to the step numbers on the diagnostic table.
2. Listen for an audible click when the level control compressor relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. This step tests for voltage at the coil side of the level control compressor relay. The ELC COMPRESSOR fuse supplies power to the coil side of the ELC COMP relay.
4. This step verifies that the ESC module is providing ground to the ELC COMP relay.
5. This step tests if ground is constantly being applied to the ELC COMP relay.
6. This step tests for a short to voltage.