OBD-II code · Powertrain (generic)

P0845 Transmission Fluid Pressure Sensor/Switch B Circuit

Electrical fault on the transmission fluid pressure sensor B circuit. Sensor B monitors a secondary hydraulic circuit such as a clutch line.

Is it safe to drive with P0845?

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

Common causes

  • Most likelySensor failed
  • PossibleWiring fault

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 B, Wiring Harness

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