OBD-II code · Powertrain (generic, extended)

P278B Kick Down Switch Circuit Range/Performance

The kick-down switch state is implausible against accelerator pedal position. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.

Is it safe to drive with P278B?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • PossibleSwitch trip point drift
  • PossibleAccelerator pedal travel out of spec
  • Less likelySensor element aged beyond calibration window

Repair at a glance

Difficulty
Easy
DIY friendly
Often, with basic tools
Typical labour
0.3–1.5 h
Emissions test
Usually unaffected
Parts involved
Kickdown Switch, Accelerator Pedal

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