P2B2C Engine Coolant Temperature Sensor 5 Circuit Range/Performance

P2B2C concerns a fifth coolant sensor whose signal is electrically valid but does not behave like coolant temperature: after a long cold soak it differs clearly from the other engine temperatures, it barely rises during warm-up although the engine heats normally, or it sits stuck at one value. CARB requires such rationality checks for coolant inputs that emission controls rely on. No manufacturer documents the set condition of P2B2C publicly; GM, which uses a sensor 5 input on the L3B and other engines, publishes only the electrical codes P2B2D and P2B2E for it. NTN-SNR names P2B2C a deviation or malfunction of the sensor 5 signal. Causes include a drifting element, a sensor in a branch with no flow because a valve or pump has failed, or poor contacts. Pure circuit faults are P2B2B, P2B2D and P2B2E.

Likely causes

Symptoms

• MIL, often after a cold start
• Heater or fan behaviour that does not match engine temperature

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, ntn-snr.com.