C066D
Service/Park Brake Chamber Pressure Sensor
Generic fault on service/park brake chamber pressure sensor — used on air-brake systems with combined service and spring-applied parking brake chamber.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
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.
- Pressure sensor failedCommon
Parts involved
- Service Park Brake Chamber Pressure Sensor
C066D 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.