OBD-II code · Powertrain (generic)

P0B0B Electric/Auxiliary Transmission Fluid Pump A Motor Supply Voltage Circuit High

The supply voltage circuit of auxiliary transmission fluid pump A motor reports a high condition. 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 P0B0B?

The car may go into limp mode (reduced power). Get it diagnosed before a long trip.

Common causes

  • Most likelyWire shorted to higher voltage
  • PossibleAlternator overvoltage
  • 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
1–5 h
Emissions test
Usually unaffected
Parts involved
Aux Trans Pump A Motor, Wiring Harness, Tcm

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