ABS light on: can you still drive, and will it pass inspection?
Updated · Autofy
ABS light on: can you still drive, and will it pass inspection?
An amber ABS light on its own means anti-lock braking is switched off: the brakes still work normally, but the wheels can lock under emergency braking, especially in the wet. You can drive carefully to a garage, leaving more distance. If it comes on together with the red brake light, brake-force distribution is affected too: stop. An ABS light that stays on fails the French contrôle technique as a major defect, and it's a failure at the UK MOT as well.
What ABS does, and what's missing when it's off
ABS stops the wheels from locking under hard braking. Sensors measure each wheel's speed; if one slows too sharply, the control unit releases and reapplies pressure dozens of times a second. The result: you can still steer while braking hard.
When the light comes on, the unit has switched ABS off as a precaution. The brakes work like an older car's: effective, but the wheels can lock and the car can plough straight on if you steer during an emergency stop.
Alone, with traction control, or with the brake light
- ABS alone: anti-lock off. Drive carefully, leave more distance, head to a garage.
- ABS and ESP / traction control: normal to see both, they share sensors. Same advice, with extra care on slippery roads.
- ABS and the red brake light: electronic brake-force distribution is affected too, and the rear can lock before the front. Stop. More in our brake light guide.
Most common causes
- A wheel speed sensor that's dirty, cracked or badly reconnected, often after new discs or a wheel bearing.
- Its wiring, damaged by debris or rubbing.
- The toothed reluctor ring the sensor reads, rusty or cracked.
- Low battery voltage, which can trigger several lights at once.
- The hydraulic unit or control module, more rarely, and the most expensive repair.
A diagnostic scan reads the fault code and usually tells you which wheel is involved, so you don't replace parts at random.
ABS and inspections
In France, an ABS light that stays on has been classed as a major defect since May 2018: the test fails and the re-test must happen within two months, after repair. The inspector also checks that the light comes on with the ignition: one that never lights up is suspicious. More on what fails in our inspection guide.
Keep a record until it's fixed
An ABS light that comes and goes tends to return, usually at the worst moment, right before an inspection. Autofy keeps the fault in your list, ranked by severity, until you mark it fixed. Every other light is in our dashboard warning lights guide.