OBD-II code · Powertrain (generic)

P071D Transmission Mode Switch B Circuit

Transmission Mode Switch B Circuit: an electrical fault is present in the circuit.

Is it safe to drive with P071D?

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

Common causes

  • Most likelyOpen in switch or wiring

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
Easy
DIY friendly
Often, with basic tools
Typical labour
0.4–1.5 h
Emissions test
Usually unaffected
Parts involved
Transmission Mode Switch B

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