OBD-II code · Powertrain (generic, extended)

P2604 Coolant Pump Control Circuit High

The electric coolant pump drive line reads above the upper threshold — usually a short to positive or a stuck-on driver stage.

Is it safe to drive with P2604?

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

Common causes

  • Most likelyDrive line shorted to positive
  • PossibleDriver stage shorted on
  • Less likelyConnector pins corroded - high contact resistance

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.5–2.5 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Electric Coolant Pump, Coolant Pump Wiring

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