Electronic Level Control (ELC)

The Electronic Level Control keeps the rear of the vehicle at a constant height. If weight is added to the vehicle, the Height Sensor Assembly turns on the Electronic Level Control (ELC) Compressor Assembly. Air is pumped into the shock absorbers until the Height Sensor Assembly senses that the vehicle is level.
An Actuator Arm is connected between the rear axle control and the ELC Height Sensor, which is mounted on the body. It turns as the vehicle height changes. The Height Sensor Assembly detects this motion and operates switches to control the air flow into and out of the rear struts.
Voltage is applied at all times to the ELC Compressor Assembly Exhaust Solenoid, ELC Relay and Height Sensor Assembly. This allows the ELC System to raise or lower the vehicle height, even with the Ignition Switch in "OFF." Voltage is also applied to the Height Sensor Assembly with the Ignition Switch in "RUN," "BULB TEST" or "START." Approximately 35 to 50 seconds after the Ignition Switch is turned to "RUN," the Compressor Motor will run for approximately 3 to 5 seconds to charge the system.
The ELC Height Sensor delays ELC Compressor Assembly operation for 17-27 seconds after a change in height. This prevents system operation during normal ride motions. In addition, the Height Sensor Assembly limits Compressor Motor run time or Exhaust Solenoid energized time to a maximum of 7 minutes.
This time limit is necessary to prevent continuous Compressor Motor operation in case of a severe system leak or Exhaust Solenoid operation. Turning the Ignition Switch to "OFF" and back to "RUN" resets the 7 minute maximum run timer.

RAISING THE VEHICLE

When a load is added to the vehicle, the vehicle body is moved downward. After a 17-27 second delay, the coil in the Compressor Motor Relay is energized and the relay contacts close. Battery voltage is applied to the Compressor Motor, which operates the Compressor and pumps air into the adjustable shock absorbers. As the struts extend, the rear of the vehicle rises. When the vehicle body reaches its original height (+/- 25 mm [+/- 1 inch]), the Height Sensor Assembly opens the Intake Control Switch, de-energizing the Relay coil and the Compressor Motor stops.

LOWERING THE VEHICLE

When a load is removed from the vehicle, the vehicle body is moved upward. When the Height Sensor Assembly has detected a "Car-High" state for 17-27 seconds, the Exhaust Solenoid is energized allowing the Exhaust Valve to open. The ELC System vents into the atmosphere, lowering the rear of the vehicle. When the vehicle body reaches its original height (+/- 25 mm [ +/- 1 inch]), the Height Sensor Assembly opens the Exhaust Control Switch, de-energizing the Solenoid and closing the Exhaust Valve.

INFLATOR

When air is needed to fill a tire, connecting the inflator hose and then turning the Inflator Switch to ON activates the Inflator Solenoid Valve and ELC Compressor. The ELC Compressor pumps and air is diverted from the ELC system to the inflator system by the Inflator Solenoid Valve.