OBD-II code · Powertrain (generic, extended)

P278C Kick Down Switch Circuit Low

Voltage on the kick-down switch line is below the expected window. 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 P278C?

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

Common causes

  • Most likelySwitch wire shorted to ground
  • PossibleSwitch stuck closed
  • Less likelyConnector pins corroded - high contact resistance

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, Wiring Harness

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