Powertrain
Definition only
Lights the check engine lamp
P2BB4: Engine Coolant Temperature Sensor 4 Circuit Intermittent/Erratic
Standardized SAE J2012 code · P2Bxx codes
What does P2BB4 mean?
The signal of engine coolant temperature sensor 4 drops out or jumps intermittently. Loose connector or noisy ground reference.
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
Symptoms
- Check engine light on
- Cooling fan runs constantly or not at all
- Cabin heater weak or excessively hot
- Possible long warm-up time or hard cold start
Common causes
- High Sensor connector not seated
- Medium Noisy ground reference
- Low Connector with intermittent contact under vibration
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of P2BB4 on the same make and model first.
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