P25A2 code meaning
Brake System Control Module A Requested MIL Illumination
Powertrain system Generic code P25xx codes Check engine light
What P25A2 means
P25A2 is a messenger code: the brake system control module has stored an emission-relevant fault of its own and asks the engine module to light the check engine lamp. GM's 2017 engine table 17OBDG04 and 2019 hybrid table 19OBDG01 watch this request continuously from three seconds after power-up and class the engine module entry itself as Type A without a separate lamp request, because the lamp is already on the brake module's behalf. GM bulletins show the spread of causes: PIC6404 for 2020 Cadillac CT4 and CT5 links it to lost front camera communication, PIT6012 for 2023 Colorado and Canyon to a weak battery with C05D3 and a spongy pedal. Volvo's technical journal 36899 cures P25A268 on many 2017–2024 models by software. Read the brake module before replacing anything. Brake module B uses P25C9.
P25A2 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P25A2
- Check engine lamp on
- ABS, stability or driver assistance warnings at the same time
- Brake pedal may feel soft in some cases
Common causes of P25A2
- Most likelyEmission-relevant fault stored in the brake control module
- PossibleWeak battery or low system voltage upsetting the brake module
- PossibleBrake or related module software needing an update
- Less likelyLost communication with a partner module such as the front camera
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Brake control module a
What each part of P25A2 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. |
| A2 | The exact fault in that area. |
What to do next
- Note P25A2 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 P25A2
What does P25A2 mean?
P25A2 means "Brake System Control Module A Requested MIL Illumination". P25A2 is a messenger code: the brake system control module has stored an emission-relevant fault of its own and asks the engine module to light the check engine lamp. It is a generic code, so it means the same on every make.
Is it safe to drive with P25A2?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P25A2 fail an emissions test?
Yes, it can. P25A2 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P25A2 to fix?
Difficulty: hard. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P25A2 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.