C0655

Circuit Description
The vehicle's rear leveling compressor motor is switched on and off via a compressor motor relay which is controlled by the suspension control module. The control module provides a switched path to ground whenever compressor activity is required. The control module continually monitors the compressor motor relay circuitry to determine if the voltage level agrees with the commanded state.


Conditions for Running the DTC
Whenever compressor activity is required.


Conditions for Setting the DTC
^ Open in the control circuit of the compressor motor relay.
^ Short to ground in the control circuit of the compressor motor relay.
^ Short to battery in the control circuit of the compressor motor relay.
^ Open in the ignition 3 voltage circuit of the compressor motor relay.
^ Open ION 3 Fuse.
^ A malfunctioning compressor motor relay.


Action Taken When the DTC Sets
^ The compressor motor relay is disabled for the remainder of the ignition cycle.
^ DTC C0655 will be stored in memory.


Conditions for Clearing the MIL/DTC
^ The suspension control module no longer detects a open, short to ground, or a short to battery in the control circuit of the compressor motor relay.
^ A history DTC will clear after not seeing the malfunction for 100 consecutive ignition cycles.
^ Using a scan tool.


Diagnostic Aids
^ The following conditions may cause a malfunction to occur:
A short to ground in the control circuit of the compressor motor relay.
^ A open in the control circuit of the compressor motor relay.
^ A short to ground in the control circuit of the compressor motor relay.
^ A short to battery in the control circuit of the compressor motor relay.
^ A open in the ignition 3 voltage circuit of the compressor motor relay.
^ A malfunction in the compressor motor relay.

Important: A leak in the air tube between the rear shocks and compressor will cause excessive running of the compressor motor. After approximately 5 minutes of continuous running without a change in body-to-wheel height or system pressure, the control module will command the compressor motor relay to the off state for the remainder of the ignition cycle.


Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
2. Command both the ON and OFF states. Repeat the commands as necessary.
3. Tests the coil of the relay for continuity.
4. Tests for voltage at the coil side of the compressor motor relay. The IGN 3 Fuse supplies power to the coil side of the compressor motor relay.
5. Verifies that the suspension control module is providing ground to the compressor motor relay.
6. Tests if ground is constantly being applied to the compressor motor relay.
7. Test for a short to voltage or an open in the control circuit of the compressor motor relay.
13. The replacement control module must calibrated.