This bulletin applies to 2014-2015 RAM 2500/3500 vehicles built on or before May 23, 2015, equipped with Auto Level Rear Air Suspension. The MIL may be on, and DTC C1556-14 (ride height air pressure sensor – circuit short to ground or open) may be stored, and the rear air suspension system is inoperative.
If DTC C1556-14 is found setting active or stored in the PCM memory, inspect the wiring harness for shorts or grounding. Repair as necessary. If no wiring issues are found, replace the air compressor. The compressor is available as P/N 68239571AA. Nitrogen is P/N NPN.