OBD-II code · Powertrain (generic)

P0843 Transmission Fluid Pressure Sensor/Switch A Circuit High

The transmission fluid pressure sensor A circuit reports voltage above threshold, indicating short to power or open ground.

Is it safe to drive with P0843?

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

Common causes

  • Most likelySignal shorted to battery
  • PossibleOpen ground 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
1–4 h
Emissions test
Usually unaffected
Parts involved
Transmission Fluid Pressure Sensor, Wiring Harness

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