Powertrain, generic (extended)

P25C7 Brake Booster Temperature Sensor A Circuit High

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

P25C7 flags a sensor A signal that is too high; GM interprets it as the temperature line shorted to supply. In the EBCM part of table 23OBDG07 for the 2023 Corvette Z06 the voltage must exceed 3.27 V five consecutive times within 0.6 s with the ignition on, and the fault is Type B with two trips to the MIL. Tables 24OBDG07 and 25OBDG03A repeat these values. Beyond a real short, an open sensor or a broken ground can also pull the signal toward the top of the range on many sensor designs, so the wiring at the booster deserves a check before the unit is replaced. Its second sensor uses the slightly lower limit of 3.14 V and the chassis code C057A. P25C6 is the low-side counterpart.

Likely causes

Sensor signal shorted to the supply line
Open sensor circuit or missing sensor ground
Temperature sensor open internally

Symptoms

  • Check engine lamp after two trips
  • Brake system warning message
  • Reduced brake assistance possible

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–2,500
Time1–4 h

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

Parts involved

electric brake boostertemperature sensorwiring harness

Related codes

P25C6P25C4C057AC05B4

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.