What does code P25BB mean?

Q: What does code P25BB mean?

Regeneration Control Switch Circuit Low. P25BB indicates that the powertrain control module (PCM) has detected a low-voltage condition on the regeneration control switch circuit, which is used to command a manual regeneration of the diesel particulate filter (DPF). The PCM expects to see a specific voltage on the signal circuit when the switch is at rest and a different voltage when the switch is pressed; a continuous low reading tells the PCM the circuit is shorted to ground or the switch is stuck closed.

DTC codes / P25xx · Vehicle speed, idle control and auxiliary inputs / P25BB

P25BBRegeneration Control Switch Circuit Low

P25BB indicates that the powertrain control module (PCM) has detected a low-voltage condition on the regeneration control switch circuit, which is used to command a manual regeneration of the diesel particulate filter (DPF). The PCM expects to see a specific voltage on the signal circuit when the switch is at rest and a different voltage when the switch is pressed; a continuous low reading tells the PCM the circuit is shorted to ground or the switch is stuck closed.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.