P25C8 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. 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.

Likely causes

Symptoms

• Brake warning that appears and disappears
• Occasional change in pedal feel

Repair estimate

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

Parts involved

Related codes

References: gsi.ext.gm.com, bosch-mobility.com.