What does code P2551 mean?

Q: What does code P2551 mean?

Torque Management Request Input Signal 'B' High. P2551 means the powertrain control module (PCM) has detected an abnormally high voltage on the torque management request input signal 'B' circuit, which is a signal used by the transmission control module or other control units to request reduced engine torque during shifts or traction events. The PCM expects this signal to stay within a calibrated voltage range, and a sustained high reading tells the PCM that the request circuit is shorted to voltage or that the requesting module is sending an invalid command.

DTC codes / P25xx · Vehicle speed, idle control and auxiliary inputs / P2551

P2551Torque Management Request Input Signal 'B' High

P2551 means the powertrain control module (PCM) has detected an abnormally high voltage on the torque management request input signal 'B' circuit, which is a signal used by the transmission control module or other control units to request reduced engine torque during shifts or traction events. The PCM expects this signal to stay within a calibrated voltage range, and a sustained high reading tells the PCM that the request circuit is shorted to voltage or that the requesting module is sending an invalid command.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

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.