OBD-II code · Powertrain (generic, extended)

P25A2 Brake System Control Module A Requested MIL Illumination

The primary brake system control module (ABS/ESC/iBooster) has requested the ECM to illuminate the MIL because of an emissions-relevant fault on its side — for example a regenerative braking fault on a hybrid that affects driveline torque flow. The original fault is in the brake module.

Is it safe to drive with P25A2?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyInternal fault in the brake module — read its DTCs

Repair at a glance

Difficulty
Medium
DIY friendly
Best left to a mechanic
Typical labour
0.5–5 h
Emissions test
Likely to fail
Parts involved
Brake Control Module A

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.