OBD-II code · Powertrain (generic, extended)

P2B29 Hybrid/EV Battery Pack Coolant Pump A Overspeed - Dry Run

The hybrid control module detects that battery pack coolant pump A is running above the calibrated maximum speed without load. Indicates dry running due to coolant loss or air ingestion.

Is it safe to drive with P2B29?

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

Common causes

  • Most likelyCoolant loss in battery loop
  • PossibleAir drawn into pump suction
  • Less likelyPack cell imbalance approaching service threshold

Symptoms

  • EV/hybrid system warning light on
  • Reduced power output or limp mode
  • Charging may fail or be slowed
  • Reduced electric range

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
1–6 h
Emissions test
Usually unaffected
Parts involved
Hybrid Battery Coolant Pump A, Battery Pack Coolant Loop

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