Automatic Level Control Sensor

The Electronic Level Control (ELC) sensor is mounted to the vehicle underbody above the rear axle, and is attached to the suspension tie rod by a short link and ball stud.

CAUTION: When a procedure requires disconnection of the ELC sensor from the tie rod, always disconnect the link at the tie rod (not at the ELC sensor arm), and take care not to bend or break the ELC sensor arm. When reconnecting the link to the tie rod, make sure that the sensor arm and link are properly orientated. Improper orientation will prevent the ELC system from operating properly and can result in damage to the ELC sensor.

The function of the ELC sensor is to control two basic circuits:
1. Compressor relay circuit.
2. Exhaust solenoid circuit.

The ELC sensor "measures" the position of the vehicle body, and energizes the ELC relay circuit if the ELC sensor arm is above the "in-trim zone" (vehicle body too low). The ELC sensor energizes the exhaust solenoid circuit if the ELC sensor arm is below the "in-trim zone" (vehicle body too high). To prevent falsely energizing either of these circuits during normal ride motions, the sensor circuit requires a consistent ELC sensor arm position (vehicle consistently too low or too high) for a minimum of 7-14 seconds prior to completing the ground to either circuit.

Additionally, the ELC sensor circuit electronically limits ELC air compressor run time and exhaust solenoid energized time to approximately 5 1/2 minutes. This time limit is necessary to prevent continuous ELC air compressor operation in the case of a severe system leak, and to prevent continuous exhaust solenoid operation when the vehicle is very lightly loaded. The electronic timer is reset whenever the vehicle ignition is switched from "OFF" to "RUN" or from "RUN" to "OFF", or when certain predetermined combinations of ELC sensor arm position and vehicle ignition position exist.