P25C8 code meaning
Brake Booster Temperature Sensor A Circuit Intermittent/Erratic
Powertrain system Generic code P25xx codes Check engine light
What P25C8 means
P25C8 is meant for a sensor A signal that drops out briefly or jumps faster than any real temperature in the booster could change, the typical footprint of a loose pin, a cracked solder joint or a wire that breaks under vibration. Each event may be too short for the low or high check to confirm, which is why this separate code exists. No manufacturer documents P25C8 publicly. GM's 2023 Corvette tables only confirm hard faults, requiring five consecutive out-of-range readings within 0.6 s for P25C6 or P25C7, so a fault that comes and goes might remain hidden there. Because an electromechanical booster such as Bosch's iBooster can also build brake pressure on its own for assistance systems, a jittery temperature input may make the unit limit its motor torque at unexpected moments.
P25C8 at a glance
- Check engine lightYes, usually on
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P25C8
- Brake warning that appears and disappears
- Occasional change in pedal feel
Common causes of P25C8
- Most likelyLoose or spread terminal in the booster connector
- PossibleWire breaking intermittently under vibration
- Less likelyCracked solder joint inside the booster electronics
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Electric brake boosterTemperature sensorWiring harness
What each part of P25C8 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| C8 | The exact fault in that area. |
What to do next
- Note P25C8 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 P25C8
What does P25C8 mean?
P25C8 means "Brake Booster Temperature Sensor A Circuit Intermittent/Erratic". P25C8 is meant for a sensor A signal that drops out briefly or jumps faster than any real temperature in the booster could change, the typical footprint of a loose pin, a cracked solder joint or a wire that breaks under vibration. It is a generic code, so it means the same on every make.
Is it safe to drive with P25C8?
Drive gently and only to a workshop. With P25C8 the car can go into limp mode (reduced power) to protect itself.
Will P25C8 fail an emissions test?
P25C8 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P25C8 to fix?
Difficulty: workshop only. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P25C8 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.