Why Are the ABS and VSA Lights On in My Honda?

By The ECU Clinic · 20 Oct 2026

Short answer: on Honda cars, ABS (anti-lock brakes) and VSA (Vehicle Stability Assist, Honda’s stability control) share one unit in the engine bay, often called the VSA modulator, and use the same wheel speed signals. So one fault usually turns on both lights, sometimes with the brake warning too. Common causes are a wheel speed sensor, low battery voltage, the brake light switch or a fault inside the ABS/VSA unit itself. The fault code tells you which.

What do the ABS and VSA lights mean?

• ABS is the anti-lock braking system. It stops the wheels locking when you brake hard.
• VSA is Honda’s stability and traction control. It brakes single wheels and can reduce engine power to help the car hold its line. A VSA light that flashes briefly on a slippery road means it is working; a light that stays on means the system has switched itself off.

VSA needs the wheel speed signals and the pump and valves that ABS uses. When the ABS side has a fault, VSA is switched off too, which is why the two lights come on together.

Is it safe to drive with the ABS and VSA lights on?

In most cases your normal brakes still work, but anti-lock braking and stability control may be off until the fault is fixed. The wheels can then lock under hard braking, and the car will not correct a skid on a wet road. Leave more distance and avoid hard stops. If the red brake warning light is on, the brake pedal feels different or the brake fluid is low, stop driving and get the car checked first. Our pick-up and delivery service can collect it.

Did someone press the VSA OFF button?

Many Honda models have a VSA OFF button. When it is pressed, a “VSA OFF” light stays on. Press the button again, or restart the car, and VSA usually switches back on. If the ABS light is on as well, or the lights stay on after a restart, there is a stored fault.

What are the common causes?

• Wheel speed sensor. Each wheel has one. A dirty, damaged or failed sensor, or its wiring, is a common cause.
• Low battery voltage. A weak battery, or one that has just gone flat, can make several modules store faults at once.
• Brake light switch. VSA uses it to know when you are braking, so a faulty switch can turn the lights on.
• The ABS/VSA unit itself. Faults inside the unit are among the Honda ABS faults we handle most often, for example 121-11 VSA Solenoid Valve Malfunction and the 81-19 yaw rate sensor code for the sensor inside the modulator.

When the VSA unit has a fault, other systems that take information from it, such as the electric parking brake and power steering, can show their own warnings too.

How do we find which part is at fault?

1. Read the fault codes. The ABS/VSA unit stores codes that point to the circuit at fault.
2. Rule out the simple causes. The VSA OFF button, sensors, wiring, the brake light switch, battery and fuses.
3. Check the unit. If the codes and tests point to the module, the pump or a sensor inside the unit, the ABS/VSA unit is the problem.
4. Tell you the options. You decide before any work starts.

Repair, used or new?

If the fault is in the ABS unit, we can repair your own Honda ABS module, or supply a used unit. Our repairs come with a 6-month warranty. See ABS pump and module repair for how the options compare, or ABS warning light causes for the ABS light on its own.

What should I send?

WhatsApp us your car model, year, chassis number and the fault codes. A photo of the dashboard or the scan tool screen also helps. You can bring the car, or just the unit, to Premier @ Kaki Bukit, or use our pick-up and delivery service.

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