P2641 is set when the Powertrain Control Module (PCM) detects that the torque management feedback signal 'B' is out of expected range or circuit malfunction. This signal coordinates engine torque output with transmission shifting and other vehicle systems. The code indicates a communication issue between the engine control system and torque management system.
The TCC or its control solenoid often fails, causing abnormal torque readings that set the code.
Damaged, corroded, or loose wiring/connectors for the torque signal circuit are the most common actual cause.
Incorrect input signals from these sensors can cause incorrect torque calculations and set the code.
Some vehicles use a dedicated torque sensor that can fail, sending erroneous signals to the PCM.
Problems in the TCM or its communication with the PCM can trigger this code.
The engine computer is very rarely the cause of P2641 and should be considered only after all other possibilities are thoroughly investigated.
No. While some may claim the computer needs replacement, the PCM is almost never the cause of this code. The issue is almost always in sensors, wiring, or transmission components.
The vehicle will likely enter limp mode with reduced power to protect the drivetrain. Driving is possible but not recommended as it may cause further damage, especially to the transmission.
No. Clearing the code without diagnosing and repairing the root cause will result in the code returning, often within the same drive cycle.
P2641 is especially common on Honda and Acura vehicles due to their specific torque management system design, but it can occur on any vehicle with electronic throttle control and torque management integration.