C066F
Service/Park Brake Chamber Pressure Too Low
Pressure in the service/park brake chamber dropped below required minimum — risk of insufficient braking force.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Common causes
Ordered by how often each turns out to be the cause.
- Air leak in brake systemCommon
Parts involved
- Service Park Brake Chamber
- Air Compressor
- Air Lines
C066F is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.