P2644
Torque Management Feedback Signal B High
Torque management
Generic OBD-II
Medium
What it means
P2644 means the ECM saw an out-of-range high value on torque management feedback signal B — a signal used to coordinate engine torque with the transmission and traction control during shifts. It's typically a wiring, connector, or module fault. The car usually still drives, but shifts can turn harsh and it may enter reduced-power mode.
Medium
Can I keep driving? Usually drivable, but shifts may be harsh and the car can drop into reduced-power/limp mode.
Common symptoms
What you'll notice
- Check-engine light on with the code stored
- Harsh or erratic shifts
- Reduced-power or limp mode in some cases
- Traction/stability control warning light
Common causes
Most likely first
- Short to voltage in the torque-feedback signal wiringLikely
- Corroded or loose connector on the signal circuitCommon
- Fault in the module or sensor supplying the feedback signalCommon
- PCM or TCM internal faultLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and scan for related network or torque codes.
- Inspect the signal wiring and connectors for a short to power.
- Check module grounds and power supplies.
- Verify the feedback signal with a scan tool against expected values.
- Address the failing module if wiring is good. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2644?+
Usually short-term, but expect harsher shifts and possible reduced-power mode. Coordination between the engine and transmission is affected, so have it looked at soon.
Can I just clear P2644?+
It returns until the signal fault is corrected. Clearing won't restore proper torque coordination.
Related codes
Often seen with P2644
Read & clear P2644 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