OBD-II code · Powertrain (generic)

P091B Gear Shift Position Circuit Range/Performance B

The gear shift position circuit B reports a circuit range/performance fault. Gear shift position feedback is unreliable on this channel.

Is it safe to drive with P091B?

The car may go into limp mode (reduced power). Get it diagnosed before a long trip.

Common causes

  • Most likelyPosition sensor failed
  • PossibleWiring fault
  • 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
Medium
DIY friendly
Best left to a mechanic
Typical labour
0.5–3 h
Emissions test
Usually unaffected
Parts involved
Gear Shift Position Sensor B, Wiring Harness, Tcm

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