Powertrain, generic (extended)

P2B2E Engine Coolant Temperature Sensor 5 Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

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.

Likely causes

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

Symptoms

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

Repair estimate

DifficultyEasyDIY possible
Parts and labour€30–300
Time0.3–2 h

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

Parts involved

engine coolant temperature sensor 5wiring harnessecm

Related codes

P2B2DP2B2BP2B2CP2BB5P2AFFP2185

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov, ntn-snr.com.