P01ED
Engine Coolant Heater B Control Circuit Low
Engine Coolant Heater B Control Circuit Low: the control-circuit voltage is below the expected range. Often a short to ground or high resistance in the wiring.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Wiring shorted to groundCommon
- Connector pins corroded - high contact resistanceLess likely
- Harness chafing through insulationLess likely
Parts involved
- Coolant Heater B
- Heater Wiring
P01ED 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.