OBD-II code · Powertrain (generic)

P01EC Engine Coolant Heater B Control Circuit/Open

Engine Coolant Heater B Control Circuit/Open: the control circuit is open. Likely a broken wire, disconnected connector, or failed actuator.

Is it safe to drive with P01EC?

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

Common causes

  • Most likelyWiring break
  • Less likelyPin pushed back out of connector body
  • Less likelyCracked solder joint inside the module or sensor

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.5–3 h
Emissions test
Likely to fail
Parts involved
Coolant Heater B, Heater Wiring

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