ABS sensor location

[nomi123]

Can anyone tell me where the ABS sensors are located? I know there is one at each wheel but I've been told there are two more in the engine somewhere. Any ideas on where they are?

[coda307]

Originally Posted by nomi123

Can anyone tell me where the ABS sensors are located? I know there is one at each wheel but I've been told there are two more in the engine somewhere. Any ideas on where they are?

Follow brake lines, they go to them

[wiswind]

There are not ABS sensors on the engine.
There are 4 ABS sensors, one at each wheel.
If you look at my pictures, where I show the brake jobs......(front and rear), you will see a "gear" with teeth on each axle.....behind the backing plate for the brake assemby at each wheel.
That "gear" is known as the "exciter ring".
There is a small magnetic pickup unit that has a wire coming from it.....located near the gear at each wheel.
This is the "sensor"......as each tooth of the gear passes the sensor, it causes the magnetic field to change, which causes a small voltage.
The result is that as you drive, a series of voltage pulses come from each sensor.......which tells the ABS system how fast each wheel is turning.
If you hit your brakes, and 1 or more wheels lock up, the ABS system can detect which wheels have locked up, and momentarily release the brake pressure for the particular wheel, or wheels that have locked up....causing the pulsing sound that you hear when you have a wheel locking up.
The system basically pulses the brakes ON and OFF.

Sometimes a sensor can, somehow, end up spaced slightly too far from the gear....causing it to not correctly sense the passing of the gear teeth.
The ABS system can detect this, as it knows that the brakes have not been applied, and 1 wheel is not giving the correct signal.
This will cause the ABS light to come on.....with a code telling what the specific problem is....and at which wheel.