S036

CODE S036 ELC COMPRESSOR RELAY SHORT TO GROUND/OPEN CIRCUIT









TEST CONDITIONS:
The RSS control module monitors the compressor relay circuit on the low-side of the coil during commanded off states. The module expects to see the circuit high.

FAULT CONDITIONS:
If the RSS control module sees the circuit low for 200 mS during an off state and appropriate decoding has occurred, a code is set.

ACTION TAKEN:
Set code, turn on "SERVICE RIDE CONTROL" message, and stop driving the relay for the remainder of the ignition cycle.

DESCRIPTION:
Leveling errors are detected via a single error feedback signal from a four-channel integrated circuit (QDM) which drives both the compressor relay and the exhaust solenoid. The RSS control module monitors this discrete feedback through all four possible leveling states (Compressor = Off & Exhaust = Off; Compressor = Off & Exhaust = On, Compressor = On & Exhaust = Off, Compressor = On & Exhaust = On) and decodes it only when all four states have been seen. All four states occur slightly after every ignition on when the leveling system goes through an Air Replenishment Cycle, as well as during normal operation. Only electrical problems with the compressor relay will be flagged. The default mode for the relay is normally open with zero current so the compressor does not operate. Compressor motor problems and pneumatic leakage problems will not set a code, but the RSS control module will shut the compress function off if no progress is made or if excessive run time occurs.

NOTES ON FAULT TREE:
[1] Refer to notes on intermittents.
[2] A temporary compressor overload (i.e. high head pressure during a cold start) may cause the fuse to blow.
[3] Refer to clearing codes.

IMPORTANT:
^ WHEN ALL DIAGNOSIS AND REPAIRS ARE COMPLETE, CLEAR CODES AND VERIFY OPERATION.