C0405: Traction Control Active Too Long

TCS regulation has been continuously active longer than allowed, suggesting persistent low-friction conditions or a sensor fault.

Symptoms

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

Most likely causes

• Persistent low-friction surface
• Wheel speed sensor drift

What to check, in order

Start with the simplest. You can tick off each step.

1. Check that the brakes respond normally and check the fluid level
2. Read the ABS codes with a multi-system scanner
3. Check the wheel sensors, connectors, and wiring
4. Compare the speeds of all four wheels in live data
5. Leave any work on the hydraulic circuit to a professional

Good to know

• Repair difficulty: medium

What each character of C0405 means

• C: Chassis
• 0: Generic code: same on every make
• 4: Subsystem depends on the code range
• 05: Specific fault in that system

Frequently asked questions

Can I keep driving with code C0405?

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 C0405?

The most common causes are: persistent low-friction surface; wheel speed sensor drift.

Sources

• en.wikipedia.org: Traction control system

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.