OBD-II code · Powertrain (generic, extended)

P2C39 Cylinder Head Temperature Sensor B Range/Performance

The ECM detects a range/performance fault on the cylinder head temperature sensor b. Reading cannot be used reliably for control.

Is it safe to drive with P2C39?

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

Common causes

  • Most likelySensor characteristic drifted
  • PossibleSensor mounting displaced
  • 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
Likely to fail
Parts involved
Cylinder Head Temperature Sensor B, Wiring Harness, Ecm

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