Generic fault on the supply voltage shared between brake pressure sensors.
High severity. Can I keep driving?The regular brakes usually keep working, but without ABS or the driver aids. Drive very carefully and go to a repair shop; if the pedal feel changes, do not keep driving.
The ABS and stability control module monitors the wheel sensors, the pump, and the solenoid valves. If it detects a fault, it may turn off these driver aids.
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Most likely causes
- Supply wiring fault
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
What each character of C05C9 means
- C: Chassis
- 0: Generic code: same on every make
- 5: Subsystem depends on the code range
- C9: Specific fault in that system
Frequently asked questions
Can I keep driving with code C05C9?
The regular brakes usually keep working, but without ABS or the driver aids. Drive very carefully and go to a repair shop; if the pedal feel changes, do not keep driving.
What causes code C05C9?
The most common causes are: supply wiring fault.
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.