Chassis
generic / SAE
P25C9
Brake System Control Module B Requested MIL Illumination
A second brake system control module (typically the redundant secondary unit on by-wire or AV-grade brake systems) has signalled an emissions-relevant fault and requested the engine controller to switch on the MIL.
SystemChassis
Typegeneric / SAE
GroupP2
Range / number5 / C9
Possible causes
- Active DTC stored in the secondary brake module high
- Communication loss interpreted as MIL request low
Inspection / repair
- Difficulty: medium
- DIY: shop recommended
- Estimated cost: 80–600 €
- Estimated time: 0.5–2.5 h
- Component: brake control module b
- Component: communication bus
- MIL / check engine light
Sources
References
sae:J2012