EF5 Air Compressor Relay Check

^ in order to determine if vehicle wiring harness has air compressor relay circuits in proper location the following test is required:

^ Using an analog ohmmeter, connect one lead to air compressor relay vehicle wiring harness connector Circuit 420 and other to a known good chassis ground.

^ Is ohmmeter reading less than 2 ohms?

YES -- Air compressor relay power Circuit 420 and ground Circuit 430B are reversed. RELOCATE these circuits to the proper location. RECONNECT air compressor relay and air suspension control module. REPEAT Service Bay Diagnostics after service is made.

NO -- Go to EF7.