OBD-II code · Powertrain (generic, extended)
P2BB4 Engine Coolant Temperature Sensor 4 Circuit Intermittent/Erratic
The signal of engine coolant temperature sensor 4 drops out or jumps intermittently. Loose connector or noisy ground reference.
Is it safe to drive with P2BB4?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor connector not seated
- PossibleNoisy ground reference
- Less likelyConnector with intermittent contact under vibration
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
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.5 h
- Emissions test
- Likely to fail
- Parts involved
- Engine Coolant Temperature Sensor 4, Wiring Harness, Ecm
Related codes
- P01E7Engine Coolant Temperature Sensor 3 Circuit Intermittent/Erratic
- P2BB5Engine Coolant Temperature Sensor 5 Circuit Intermittent/Erratic
- P2BBAEngine Coolant Temperature Sensor 6 Circuit Intermittent/Erratic
- P2BB1Alternative Fuel Consumption Too High
- P2BB2Alternative Fuel Tank Empty
- P2BB3Fuel Pump Secondary Circuit Performance
- P2BB6Engine Coolant Temperature Sensor 6 Circuit
- P2BB7Engine Coolant Temperature Sensor 6 Range/Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.