Code S038, ELC Exhaust Valve Short To Ground/Open: Description

Leveling errors are detected via a single error feedback signal from a 4-channel integrated circuit (QDM) which drives the compressor relay and the exhaust solenoid. The RSS module monitors this discrete feedback through all 4 possible leveling states and decodes it only if all 4 states have been seen. Leveling states include:

• Compressor OFF, Exhaust OFF
• Compressor OFF, Exhaust ON
• Compressor ON, Exhaust OFF
• Compressor ON, Exhaust ON.

All 4 states occur shortly after every ignition ON cycle when the leveling system goes through an air replenishment cycle, as well as during normal operation. Only electrical problems with the exhaust valve solenoid will be flagged.

The default mode for the valve is normally closed with zero current so no exhaust occurs. Pneumatic blockage problems will not set a code, but the RSS module will shut the exhaust function off if no progress is made or if excessive ON time occurs.

1. See NOTES ON INTERMITTENTS  under TESTING & DIAGNOSIS.
2. This code may be caused by a compressor overload which could cause the fuse to blow. Low battery voltage may also cause this condition by overloading the compressor.

Fig 1: Code S038 - ELC Exhaust Valve Short to Ground/Open (1 of 2)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code S038 - ELC Exhaust Valve Short to Ground/Open (2 of 2)

Courtesy of GENERAL MOTORS CORP.