Suspension Control Module: Description and Operation

The Control Module (CM), controls the ground circuits for the compressor relay and the exhaust valve solenoid. A microprocessor within the CM limits the compressor pump operation time to between 140 and 160 seconds, to prevent damage to the compressor motor.
In addition, an air regeneration cycle is controlled by the CM. If the height sensor signal is neutral or high, for 22 to 28 seconds, after the ignition switch is turned to the ON position, the compressor will run from 2 to 6 seconds.
To prevent excessive cycling, a 12 to 18 second delay is incorporated in the microprocessor.