Answer
Dec 23, 2025 - 09:16 AM
When the ABS light comes on, it means the anti-lock braking system has detected a fault and shut itself off. Your normal brakes will still work, but the ABS won’t step in during hard braking until the issue is fixed.
The most common reasons on a Toyota Sienna are:
- Wheel speed sensor going bad or getting dirty
- Damaged wiring near a wheel (very common if it’s seen rough roads)
- Weak battery or low voltage causing the ABS module to throw a fault
- ABS fuse or relay issues
- Less often, a problem with the ABS pump or control module
Sometimes it’s something simple like road grime on a sensor, other times it needs proper testing. The key thing is the ABS system stores fault codes, and those codes tell you exactly where the problem is.
The service & repair manual covers ABS diagnosis in detail — how to read the codes, test sensors, check wiring, and verify the pump and module before replacing anything.
If you want, tell us the model year of your Sienna and whether the light is on all the time or comes and goes. We can point you in the right direction from there.
