P2638Torque Management Feedback Signal A Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- How the car detects it
- P2638 says the torque feedback for request A is present but its value does not fit the situation, for example an engine torque figure that drifts away from what the transmission expects during a shift. Honda documents it on its nine-speed automatic: on low-mileage 2016 Pilots the MIL lit and the gear indicator flashed because the idle learn had not been done properly before delivery, so the fix is a PCM reset with the HDS and a correct idle relearn. Service bulletins 16-008 (Pilot) and 16-012 (Acura TLX V6) later improved the torque accuracy monitoring behind P2638 by TCM software, again followed by an idle learn. Unlike P2637, where the engine ignores the request, here the reported torque is implausible. Drivers notice rough or delayed shifts.
- What you may notice
- MIL on and gear position indicator flashing
- Rough or delayed gear changes
- Likely causes
- LikelyIdle learn not completed after PCM reset or delivery
- PossibleOutdated transmission software with oversensitive torque monitoring
- RareEngine torque estimate skewed by air leaks or sensor errors
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €50 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.