This code indicates that the powertrain control module has detected an open circuit in the control circuit for the reductant injection air pump, which is part of the diesel SCR (Selective Catalytic Reduction) emissions system. The air pump helps atomize and deliver the reductant (typically Diesel Exhaust Fluid) into the exhaust stream to reduce NOx emissions. An open circuit means the PCM cannot electrically command or detect the pump motor.
The pump motor itself has failed internally, creating an open circuit. This is the most common cause and the pump is the primary suspect for this code.
Chafed, broken, or corroded wiring between the PCM and the air pump can create an open circuit. Harness routing near hot exhaust components makes this a frequent failure point.
The connector at the air pump or at the PCM can develop corrosion, bent pins, or come partially loose, interrupting the circuit.
An open fuse or failed relay in the reductant air pump power feed can mimic an open circuit condition and set this code.
Extremely rare. A failed driver circuit inside the PCM could theoretically cause this code, but this is the least likely cause and should only be considered after all wiring, connectors, fuses, and the pump itself have been definitively ruled out.
You may be able to drive for a limited time, but the vehicle will likely enter a derate or reduced power mode, and continued driving risks further emissions system issues. It should be diagnosed and repaired promptly.
Almost never. Drivers are sometimes told to replace the PCM for this code, but the real cause is nearly always the reductant air pump itself, damaged wiring, or a corroded connector. The PCM should be the last component tested and only replaced if its driver circuit is definitively proven faulty.
Yes. The reductant injection air pump is part of the SCR system that uses Diesel Exhaust Fluid (DEF) to reduce NOx emissions. This code means the pump that helps deliver that fluid is not electrically functioning.
Difficulty varies. A blown fuse or corroded connector can be a simple fix, while a failed pump or damaged harness may require more labor. Accurate diagnosis is key to avoiding unnecessary parts replacement.