P2640
Torque Management Feedback Signal A High
Powertrain torque management
Generic OBD-II
Medium
What it means
P2640 means the torque-management feedback signal 'A' — shared between the engine and transmission controllers to coordinate torque — reads abnormally high. That can throw off shift quality and power delivery.
Medium
Can I keep driving? Drivable in most cases, but the transmission may shift harshly or the engine may limit power until the fault clears.
Common symptoms
What you'll notice
- Check-engine light on
- Harsh or abrupt gear shifts
- Reduced engine power or limp mode
- Stored transmission codes / transmission MIL
Common causes
Most likely first
- Short-to-voltage or open in the torque-signal circuit between the ECM and TCMLikely
- Corroded or loose connector on the torque-management circuitCommon
- Poor ground affecting the signal referenceCommon
- Faulty transmission control module (TCM)Less often
- Faulty ECM or mismatched module softwareLess often
How to diagnose & fix
Work through it in order
- Read codes from both the engine and transmission modules and review freeze-frame data.
- Inspect the torque-signal wiring and connectors between the ECM and TCM for shorts or opens.
- Check the associated grounds and reference circuits.
- Confirm both modules have compatible, up-to-date software.
- If wiring checks out, test the TCM/ECM and replace the faulty module. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2640?+
Usually yes for a short trip, but harsh shifts and power loss can be unsafe in traffic. Have it diagnosed soon.
Can I just clear P2640?+
It'll return until the circuit or module fault behind the high signal is fixed.
Related codes
Often seen with P2640
Read & clear P2640 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