P2638: owner reports and bulletins

Powertrain (generic, all makes). We haven't written the explanation for this code yet. Below is what owners and manufacturers have filed with NHTSA.

Got P2638 on your scanner? Tell the mechanic your year, make, model and any symptoms and you'll get the likely cause and what to check first. Ask about this code.

What owners report to NHTSA

10 complaints filed with NHTSA mention P2638, 10 of them since 2015, across 4 different models. The component owners most often filed it under: engine.

Most-reported models

VehicleComplaintsModel years reported
HONDA PILOT52016, 2017

Manufacturer service bulletins that name P2638

1 technical service bulletins and manufacturer communications filed with NHTSA mention P2638, from 1 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:

  • HONDA PILOT (2016), bulletin 10100176: SERVICE NEWS ARTICLE - DO YOU HAVE A FAIRLY LOW MILEAGE VEHICLE IN YOUR SHOP WITH THE MIL ON, THE GEAR POSITION INDICATOR BLINKING, AND A/T DTC P2638 (TORQUE FEEDBACK SIGNAL A RANGE/PERFORMANCE)? CHANCES ARE THE IDLE LEA…

Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.