Coolant Heater B Control Circuit High
The control circuit of coolant heater B reports a control circuit high condition. Auxiliary preheating of the coolant cannot be commanded as expected.
Affected components
- Coolant heater b
- Wiring harness
- Ecm
Common causes
- High likelihood: Control wire shorted to B+
- Medium likelihood: Open heater element
- Low likelihood: Connector pins corroded - high contact resistance
Diagnostic notes
- The malfunction indicator lamp may illuminate
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.