Flash: Air Suspension Control Module (ASCM) Updates
This bulletin involves reprogramming the ASCM with the latest available software.
Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that one or more of the following DTCs have been set:C220C-48 - Active Suspension Module Internal-Supervision Software Failure. C211B-92 - Ignition Run/Start Input-Performance Or Incorrect Operation. C156C-7A - Ride Height System Air Leak-Fluid Leak Or Seal Failure. In addition the customer may describe:Excessive operation or noise from air suspension system when vehicle is stationary. "Air Suspension Disabled" message when attempting Bed Lowering Mode (BLM). Excessive compressor valve cycling following a cold start(Diesel engine only). Erroneous "Bed Low Achieved" message through the Instrument Panel Cluster (IPC), when requesting lowering, even though the truck didn't physically lower.
Ride height changes/valve actuations without operator request on rough roads.
