P2641
Torque Management Feedback Signal B
Transmission / torque management
Generic OBD-II
Medium
What it means
P2641 sets when the powertrain computer sees a problem with torque-management feedback signal B — the data the engine and transmission controllers share to coordinate shifts and power. A fault here can cause harsh or poorly timed shifts and may put the transmission into a protective failsafe mode.
Medium
Can I keep driving? Usually yes, but shifting or power delivery may feel off — the transmission may enter a protective mode. Get it checked before long trips.
Common symptoms
What you'll notice
- Check-engine light on
- Harsh, delayed, or poorly timed gear shifts
- Transmission entering a limited 'failsafe' mode
- Possible reduced engine power
Common causes
Most likely first
- Wiring or connector fault in the torque-management signal circuit between modulesLikely
- Poor electrical connection or ground affecting the shared signalCommon
- Software or calibration mismatch between the engine and transmission controllersCommon
- Faulty transmission control module or PCMLess often
How to diagnose & fix
Work through it in order
- Scan both engine and transmission modules and check for related codes (P2640, P2642, P2643, P0700).
- Inspect the wiring and connectors carrying the signal between modules for damage or corrosion.
- Check grounds and power supplies to the affected controllers.
- Verify both modules have the correct, up-to-date calibration.
- If wiring and software are good, diagnose the transmission control module or PCM.
FAQ
Quick answers
Is it safe to drive with P2641?+
You can usually drive to a shop, but shifts may feel harsh and the transmission may limit itself. Avoid long trips or heavy loads until it's diagnosed.
Can I just clear P2641?+
Clearing it doesn't fix the underlying signal fault — it returns and the transmission may keep going into failsafe.
Related codes
Often seen with P2641
Read & clear P2641 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX