OBD-II code · Chassis

C066E Service/Park Brake Chamber Pressure Too High

Pressure in the service/park brake chamber exceeded safe limit.

Is it safe to drive with C066E?

The car may go into limp mode (reduced power). Get it diagnosed before a long trip.

Common causes

  • Most likelyPressure regulator stuck

Symptoms

  • ABS warning light on
  • ESC/stability control deactivated
  • Possible reduced brake assist
  • Speedometer may behave erratically

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
2–6 h
Emissions test
Usually unaffected
After the fix
A drive cycle is needed before the light stays off
Parts involved
Service Park Brake Chamber, Air Compressor

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