Fault Family System: Powertrain (P-Codes) 5 SAE Codes

Brake Booster Temp Sensor

Diagnostic & Technical Explanation

Code P25C4 (Brake Booster Temperature Sensor A Circuit) sets when the ECM/brake module sees an open, shorted, implausible, or intermittent signal from the temperature sensor inside the electric or hydraulic brake booster, used to protect the booster motor from thermal overload during repeated hard stops. Causes are a corroded connector at the booster assembly, chafed wiring in the firewall harness, or a failed internal thermistor that requires booster-level service.

These 5 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 5 times.

Codes in this family (5)

Code	Definition	Repair coverage
P25C4	Brake Booster Temperature Sensor A Circuit	3 ranked fixes
P25C5	Brake Booster Temperature Sensor A Circuit Range/Performance	3 ranked fixes
P25C6	Brake Booster Temperature Sensor A Circuit Low	3 ranked fixes
P25C7	Brake Booster Temperature Sensor A Circuit High	3 ranked fixes
P25C8	Brake Booster Temperature Sensor A Circuit Intermittent/Erratic	3 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here:

Procedures 2..n after the first-listed procedure
Aftermarket parts cost ranges in USD (est_parts_cost_min/max_usd)
Professional labor-hour estimates (est_labor_hours)
Step-by-step diagnostic and repair instructions
Replacement-part mappings and catalog lookups
6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)

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