P2BB4

Engine Coolant Temperature Sensor 4 Circuit Intermittent/Erratic

Moderate severity

The signal of engine coolant temperature sensor 4 drops out or jumps intermittently. Loose connector or noisy ground reference.

Common causes

Sensor connector not seated
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $60-280
Noisy ground reference
A plausible cause — test and verify before replacing parts.
medium
Typical part cost: $60-280
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First things to check

1Confirm the code with a scan tool and check for additional related codes.
2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.

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Related codes

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Frequently asked questions

What does P2BB4 mean?

P2BB4 means "Engine Coolant Temperature Sensor 4 Circuit Intermittent/Erratic". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.

What are the most common causes of P2BB4?

sensor connector not seated; noisy ground reference; connector with intermittent contact under vibration — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.

Can I keep driving with this code?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.

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