Powertrain
Definition only
Lights the check engine lamp
P2B74: Coolant Heater A Control Circuit High
Standardized SAE J2012 code · P2Bxx codes
What does P2B74 mean?
The control circuit of coolant heater A reports a control circuit high condition. Auxiliary preheating of the coolant cannot be commanded as expected.
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
Common causes
- High Control wire shorted to B+
- Medium Open heater element
- Low Connector pins corroded - high contact resistance
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of P2B74 on the same make and model first.
P2B74 in the community
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