C066E

Service/Park Brake Chamber Pressure Too High

Severity

⚠️ Medium

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$111–333 (est.)

Symptoms

The brake system fault indicator is on
The parking brake may engage spontaneously
Difficulty releasing the parking brake

Causes

Pressure reducer malfunction
Brake valve stuck
Leak in the pneumatic system
Pressure sensor malfunction
Wiring harness damage

How to Fix

Check system pressure
Inspect air lines for leaks
Check the operation of the brake valve
Check the pressure sensor and its circuits
Replace faulty components

Related codes

C0660 C0661 C0665