OBD-II code · Powertrain (generic)

P0791 Intermediate Shaft Speed Sensor A Circuit

The TCM detects an electrical fault on the intermediate shaft speed sensor A circuit. Used to compute shift slip and torque converter behavior.

Is it safe to drive with P0791?

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

Common causes

  • Most likelySpeed sensor failed
  • PossibleWiring open or shorted

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
Often, with basic tools
Typical labour
0.5–3 h
Emissions test
Usually unaffected
Parts involved
Intermediate Shaft Speed Sensor, Wiring Harness

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