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.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Wiring breakCommon
- Pin pushed back out of connector bodyLess likely
- Cracked solder joint inside the module or sensorLess likely
Parts involved
- Coolant Heater B
- Heater Wiring
P01EC is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.