Torque Management Feedback Signal A High
The P2640 code means the vehicle's onboard diagnostic system has detected: Torque Management Feedback Signal A High. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $100 - $800 (parts and labor)
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Common Symptoms
- Harsh bumpy shifts
- Unnecessary engine torque reduction
- Sluggish acceleration response
- Transmission shifts feel abrupt
Probable Causes (Ranked by Likelihood)
- ECM overreporting torque output Very High
- Short to voltage in torque signal circuit High
- Incorrect ECM calibration after service Moderate
- Aftermarket tune affecting torque values Low
Step-by-Step Diagnostic Procedure
-
Compare reported torque to dynamometer or calculated values
-
Check torque signal circuit for short to power
-
Verify ECM calibration matches vehicle specifications
-
Remove aftermarket tunes and retest
Frequently Asked Questions
Why are my shifts so harsh with P2640?
The TCM thinks the engine is producing more torque than it actually is, so it applies excessive clutch pressure and aggressive torque reduction during shifts.
Can an aftermarket tune cause P2640?
Yes. Performance tunes that modify torque reporting can cause the TCM to receive incorrectly high values, disrupting shift quality.
Will P2640 cause transmission wear?
Harsh shifting puts extra stress on transmission clutch packs and bands, potentially accelerating wear and reducing transmission lifespan.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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