P2B2E: Engine Coolant Temperature Sensor 5 Circuit High

P2B2E is stored when the fifth coolant sensor shows a resistance so high that only an open circuit, an unplugged connector or a line shorted to voltage can explain it; the NTC curve would put the coolant below −60 °C. GM sets it once the channel exceeds about 298 kΩ in the 2019 L3B tables or about 174 kΩ in the 2025 ECM tables, for 5 s within 6 s, after an engine run time above 10 s or with intake air above −20 °C; Type B, MIL after two trips. As with sensor 4, GM's table names the radiator coolant sensor in this row although the low fault is assigned to sensor 5. GM bulletin 21-NA-149 includes P2B2E among the results of chafed engine harnesses on 2019–2021 light-duty pickups. Supplier NTN-SNR's catalogue has it as an excessive sensor 5 signal. The grounded case is P2B2D.

Medium severity. Can I keep driving?Watch the temperature gauge. If it climbs or a warning appears, stop the car in a safe place and turn off the engine: overheating can cause serious damage.

Symptoms

MIL after two trips
Sensor 5 reads around −40 °C or lower in live data
Engine runs on a substitute temperature value

Most likely causes

Open signal or ground wire, or unplugged connector
Chafed engine harness interrupting the circuit
Open sensor 5 element

What to check, in order

Start with the simplest. You can tick off each step.

With the engine cold, check the coolant level; never do this when the system is hot
Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
Check the actual temperature in live data
Make sure the fan comes on when it should
Check the thermostat and connector
Measure the sensor and replace it if its readings do not make sense

Good to know

Repair difficulty: easy
It affects emissions.

What each character of P2B2E means

P: Powertrain: engine and transmission
2: Generic code: same on every make
B: Subsystem depends on the code range
2E: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2B2E?

Watch the temperature gauge. If it climbs or a warning appears, stop the car in a safe place and turn off the engine: overheating can cause serious damage.

What causes code P2B2E?

The most common causes are: open signal or ground wire, or unplugged connector; chafed engine harness interrupting the circuit; open sensor 5 element.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.