Torque Management Feedback Signal A Low
The P2639 code means the vehicle's onboard diagnostic system has detected: Torque Management Feedback Signal A Low. 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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What Are the Symptoms of P2639?
- Transmission flares during shifts
- Delayed engagement from stop
- Reduced power feeling
- Check engine and traction lights on
What Causes P2639? (Most Likely First)
- ECM torque output signal low Very High
- Ground fault in torque signal circuit High
- ECM underreporting torque due to sensor error Moderate
- TCM receiving attenuated signal Low
Can I Still Drive with P2639?
Short distances only. P2639 is rated moderate severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
Why does my transmission flare with P2639?
The TCM thinks engine torque is lower than actual, so it does not apply enough clutch pressure during shifts, causing RPM flare between gears.
What is a transmission flare?
A flare occurs when engine RPM rises momentarily between shifts instead of transitioning smoothly. It feels like the transmission briefly slips.
Can P2639 damage my transmission?
Prolonged shifting with incorrect torque data can cause increased clutch wear and overheating. Repair to prevent long-term transmission damage.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P2639?
-
Monitor reported torque vs expected for current load
-
Check torque signal wiring for ground faults
-
Verify MAP/MAF and throttle sensors are accurate
-
Test CAN bus signal integrity
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Which Vehicles Commonly Get P2639?
- 2010-2020 Toyota Highlander
- 2012-2019 Honda Pilot
- 2008-2018 Ford Explorer
- 2011-2020 Chevrolet Traverse
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