OBD-II code · Powertrain (generic, extended)

P256E Engine Idle Speed Selector Sensor/Switch Circuit Intermittent/Erratic

The idle-speed selector signal jumps or drops out — usually a worn rotary contact or vibration. 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 P256E?

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

Common causes

  • Most likelyWorn rotary contact
  • Less likelyConnector with intermittent contact under vibration
  • Less likelyHarness routed against vibrating component

Symptoms

  • Check engine light on
  • Idle speed too high, too low, or unstable
  • Possible stalling at idle or after cold start

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.3–1.5 h
Emissions test
Usually unaffected
Parts involved
Idle Speed Selector Switch

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