Continuously Variable Road Sensing Suspension (Cvrss)

Fig. 70 Code RS0036: ELC Compressor Relay Short To Ground/Open Circuit.:

DTC RS0036 ELC Compressor Relay Short To Ground/Open Circuit:

TEST CONDITIONS:
The CVRSS compressor relay output is a low-side drive, switched to ground by the CVRSS control module whenever compressor activity is required. The control module monitors the compressor relay circuit on the low side of the coil during commanded off states, and expects to see a high voltage on the circuit.

FAULT CONDITIONS:
If the CVRSS control module sees a low voltage on the circuit for 200 mS during a commanded off (high voltage) state, an ELC compressor relay short to ground/open circuit fault condition is detected.

ACTION TAKEN:
Set fault code and stop driving the compressor relay for the remainder of the ignition cycle.

DESCRIPTION:
The compressor relay low-side drive output from the control module is continually monitored to determine if the voltage level agrees with the commanded state. When the compressor relay is commanded to the off state, a high voltage level (battery voltage) is expected. If a low voltage level is present, most likely due to a short circuit to ground or an open circuit in the relay coil or wiring, a fault condition is suspected. If this condition exists for 200 mS, the control module will set the fault code, turn on the "SERVICE RIDE CONTROL" message, and disable the compressor relay output. Recovery is not attempted until ignition is cycled off and on.

This fault condition is detectable only when the compressor relay output is commanded to the off state which occurs whenever compressor activity is not required. Only electrical problems with the compressor relay will be flagged. Compressor motor problems and pneumatic leakage problems will not set a code but the CVRSS control module will shut off the compressor if no progress is made or if excessive run time occurs.

NOTES ON FAULT TREE:
1. Refer to Intermittant.
2. A temporary compressor overload (i.e., high head pressure during a cold start) may cause the fuse to blow.
3. Clear codes. Clearing Diagnostic Trouble Codes