What are the common causes of P2643?

Torque management feedback B wire shorted to ground. Failed torque feedback B sensor or actuator. Corroded feedback B connector. Low battery voltage. ECM or TCM fault on the feedback B input.

Check battery voltage and charging. Read torque management feedback B live data. Test the feedback B signal wire for a short to ground. Inspect the feedback B connector. Verify the feedback B signal at the ECM or TCM. Clear the code and retest.

P2643

Torque Management Feedback Signal B Low

System: Computer output circuits (P code)
Lamp: Check Engine Light
Category: Powertrain - Computer and Auxiliary Controls

What it means

P2643 means Torque Management Feedback Signal B Low.

Check these first

Torque management feedback B wire shorted to ground
Failed torque feedback B sensor or actuator
Corroded feedback B connector
Low battery voltage
ECM or TCM fault on the feedback B input

What to do next

Check battery voltage and charging
Read torque management feedback B live data
Test the feedback B signal wire for a short to ground
Inspect the feedback B connector
Verify the feedback B signal at the ECM or TCM
Clear the code and retest

Look up another code

Code or symptom

Enter a full code or a symptom. Press / to search. How to read a code

Type a code above, or start from a symptom or a common code.

Updated

Generic SAE J2012 definition. Last updated 2026-10-10.