08-175-21

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:U0132 - Loss of Communication with Air Suspension Control Module. C15E1-97 - Left Rear Air Spring Intake - Component or System Operation Obstructed or Blocked. C220C-48 - Active Suspension Module Internal-Supervision Software Failure(2019 MY Only). C211B-92 - Ignition Run/Start Input-Performance Or Incorrect Operation(2019 MY Only). C156C-7A - Ride Height System Air Leak-Fluid Leak Or Seal Failure(2019 MY Only). In addition the customer may describe:Air suspension system is inoperable. During key ?On? or while driving, the ?service air suspension? light illuminates. Air spring deflated or ruptured. Right/left rear suspensions sits lower than the other side. Chime and "Service Air Suspension Immediately" message appeared in the cluster for 5 seconds. Excessive operation or noise from air suspension system when vehicle is stationary(2019 MY Only). "Air Suspension Disabled" message when attempting Bed Lowering Mode (BLM)(2019 MY Only). Excessive compressor valve cycling following a cold start(2019 MY with 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.