OBD-II code · Powertrain (generic, extended)

P27B6 Internal Control Module Transmission Speed Sensor Performance

The internal speed sensor processing logic in the transmission control module produces implausible results.

Is it safe to drive with P27B6?

Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.

Common causes

  • Most likelyInternal software logic fault
  • PossibleAged input capture circuitry drifts
  • Less likelySensor element aged beyond calibration window

Symptoms

  • Check engine or transmission warning light on
  • Harsh, delayed, or missing shifts
  • Possible limp mode (locked in one gear)
  • Slipping or shuddering during gear changes

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
1–4 h
Emissions test
Usually unaffected
Parts involved
Tcm, Speed Sensors

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.