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I have noticed the stability control light blinking on my car at two different situations.

One situation is when steering on an icy road. In this case, I do not hear the sound from the ABS. In fact, the only way I could know that I'm driving near the limits was the light blinking!

However, I have also noticed that the stability control light blinks when braking hard on an icy road, so hard that the ABS starts to operate. In this case, I very clearly hear the sound from the ABS. To make it clear, I wasn't steering the car at all in this case, just braking hard.

I have understood that ABS and stability control systems are separate from each other. Now, why does the light blink when driving straight and braking? Does the light mean that the car is doing something else than operating the ABS as well? Or is the light connected so that merely the ABS operating will also cause the light to blink? In my opinion, if the light is connected in this way, it is unnecessary, as you anyway hear and feel the ABS operating from the sound and from the brake pedal. On the other hand, stability control operation cannot be heard or felt in any way, so the stability control light clearly has an important role.

The car is a 2016 Toyota RAV4 hybrid.

  • What does the manual say about this indicator? – Hobbes Feb 5 '17 at 14:59
  • This is going to be vehicle dependent, as it will depend on how the manufacturer has engineered and programmed both the ABS and stability control to work. – Pᴀᴜʟsᴛᴇʀ2 Feb 5 '17 at 15:33
  • ABS and stability control are related (both require control of the brake system, both use the same sensors), so I'd be surprised if they were separate systems. – Hobbes Feb 5 '17 at 16:23
  • I have understood that stability control uses sensors that ABS does not have: yaw/roll rate, acceleration, steering wheel sensors etc. However, wheel speed sensor is obviously used both for ABS and stability control, as are the brakes. However, I'll try to remember to read the manual tomorrow when I next use the car. It is quite short manual and omits many important details, but there may be explanations for the warning lights in it. – juhist Feb 5 '17 at 16:32
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I believe this is because when you brake, your tires slip different amounts. If ABS equally turned on/off the brakes then you could start spinning. But if vehicle detects that you will start spinning. Vehicle systems can try to counteract this by regulating the on/off times of the brakes. Therefore it may turn on the stability control light. This may be even a bigger issue if you were not going exactly straight when you started breaking.

Here is link to the manual of the car: http://www.toyota.com/t3Portal/document/om-s/OM42A41U/pdf/OM42A41U.pdf I believe you can disable VSC, see page 300

I would suggest asking to Toyota since your car is probably still under warranty but I expect only the people who designed the systems would know the answer. You may just get an answer which is designed to make you feel that everything is ok :)

Manual says the following about VSC:

VSC (Vehicle Stability Control)

Helps the driver to control skidding when swerving suddenly or turning on slippery road surfaces

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