The electronic suspension control (ESC) module provides a common regulated voltage of approximately 5 volts to all 4 of the body-to-wheel suspension position sensors and the air pressure sensor. The ESC module monitors this reference voltage for any malfunctions that could prevent it from outputting a regulated 5 volts.

This diagnostic procedure supports the following DTC:

DTC C0870 Device Voltage Reference Output (Signal or 1) Circuit

Continuously with the ignition ON

The ESC module senses a sensor reference voltage of less than 4 volts or greater than 6 volts.

Important: Ignition cycle counting is used by the ESC module to detect faults in the system. The objective is to eliminate false/intermittent codes while maintaining an acceptable level of system performance. The operation of the ignition cycle counting requires that a fault condition be present for 4 consecutive ignition cycles before it will set the fault code and display the SERVICE RIDE CONTROL message. If a fault code is present, without a fault being current, the system will go into one or more degraded modes without displaying a message. Resetting the ignition cycle counter is done by clearing codes with a scan tool. Clearing codes will override ignition cycle counting for one ignition cycle. Therefore, a fault condition will set the fault code immediately if it occurs on the first ignition cycle after the codes are cleared.

The numbers below refer to the step numbers on the diagnostic table.

3. This step tests all suspension position sensor reference voltage circuits.

4. This step tests the 5-volt reference circuit of the air pressure sensor for a short to ground and a short to voltage.

6. Clear DTCs and check to see if the DTC will reset.