Brakes, ABS & Stability fault codes
ABS, stability and foundation-brake faults — wheel-speed sensors, modulator valves, air pressure, steering-angle and stability inputs, the trailer ABS link, and the wheel-based vehicle speed the ABS ECU broadcasts to the rest of the truck. These are the codes that turn a roadside inspection into an out-of-service order: a lit trailer ABS lamp is a violation whether or not the truck stops fine.
All 41 brakes, abs & stability SPN/FMI and OBD codes in the knowledge base are listed below — each with what it means, how serious it is, the most-likely causes, and what to check first.
Brakes, ABS & Stability codes (41)
Other systems
Cooling, lubrication, HVAC and chassis/cab codes are listed on the fault code lookup, along with the search box that covers every code.
General diagnostic guidance for heavy-duty diesel equipment (Cummins, Detroit, PACCAR, Volvo, Mack and more). Not a substitute for a scan-tool diagnosis on your specific truck.