OBD-II code · Powertrain (generic, extended)

P274D Transmission Fluid Temperature Sensor C Circuit High

The third transmission fluid temperature sensor signal is above the upper diagnostic threshold. 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 P274D?

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

Common causes

  • Most likelyOpen sensor element
  • PossibleSignal wire shorted to the 5 V reference
  • Less likelyConnector pins corroded - high contact resistance

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
Medium
DIY friendly
Best left to a mechanic
Typical labour
0.8–3 h
Emissions test
Usually unaffected
Parts involved
Trans Fluid Temp Sensor C, Wiring Harness

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