P2B25 code meaning
Hybrid/EV Electronics Coolant Temperature Sensor C Circuit Range/Performance
Powertrain system Generic code P2Bxx codes Check engine light
What P2B25 means
P2B25 is the plausibility code for the third electronics coolant sensor. The signal is electrically sound, but its value cannot be right, for example because sensor C still reads cold while sensors A and B in the same loop have long warmed up, or because it jumps by an amount the coolant could not follow. No manufacturer publishes a set condition for P2B25. NTN-SNR describes it as a deviation or malfunction of the sensor C signal, and CARB asks for rationality checks on inverter thermal management inputs. GM's after-soak comparison for sensor A (P0CEF) illustrates the method. A sensor C that sits near a component with its own heat, such as the charger, can also mislead the test if the pump has stopped or the loop holds air. Electrical faults of sensor C go to P2B26 and P2B27.
P2B25 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 2.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P2B25
- Fault code set after a cold start or a long drive
- Cooling system reacting inconsistently
- Possible limitation of charging power
Common causes of P2B25
- Most likelySensor C reading drifted away from the true temperature
- PossibleAir in the loop or a weak pump leaving sensor C without flow
- PossibleCorrosion in the sensor C connector
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hybrid electronics coolant temp sensor cWiring harnessHybrid control module
What each part of P2B25 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| B | Area: hybrid propulsion. |
| 25 | The exact fault in that area. |
What to do next
- Note P2B25 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2B25
What does P2B25 mean?
P2B25 means "Hybrid/EV Electronics Coolant Temperature Sensor C Circuit Range/Performance". P2B25 is the plausibility code for the third electronics coolant sensor. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B25?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2B25 fail an emissions test?
Yes, it can. P2B25 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2B25 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. This is a job for a workshop.
Will P2B25 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.