C05xx codes: chassis control module
2 codes in this range, all generic — the same meaning on every make. Anti-lock brakes and traction and stability control: wheel-speed sensors, the hydraulic unit with its valves and pump, the brake switch, and the steering-angle, yaw-rate and lateral-acceleration sensors.
What usually causes codes in this area
- A dirty, damaged or failed wheel-speed sensor or its tone ring
- Wiring near the wheels, exposed to water, salt and debris
- A faulty brake-light switch
- A fault in the hydraulic unit or the module
Can you keep driving?
Normal braking still works, but ABS and stability control may be off: brake earlier on wet or icy roads and get it checked soon. If the red brake warning lamp is on too, or the pedal feels different, stop and have the brakes inspected.
All C05xx codes
Read the codes from your own car
Plug an inexpensive Bluetooth LE or Wi-Fi OBD2 adapter into the port under the dashboard, and Brimly on your iPhone reads the stored, pending and permanent codes, explains each one offline and clears them once the fault is fixed. OBD diagnostics are part of Brimly Forever, a one-time purchase.
Requires iOS 18.1 or later. Free to download, with optional in-app purchases.