OBD-II code · Powertrain (generic, extended)

P2840 Shift Fork D Position Circuit

The TCM cannot read a valid position signal from shift fork D position sensor. Selector engagement state is unknown.

Is it safe to drive with P2840?

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

Common causes

  • Most likelyPosition sensor failed
  • PossibleWiring or connector fault

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
3–10 h
Emissions test
Usually unaffected
Parts involved
Shift Fork D, Shift Fork Position Sensor D, Wiring Harness

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