ABS stands for anti-lock braking system which helps the tires maintain contact with the road while you’re braking to help prevent the wheels from locking up which can cause an uncontrollable skid.
The heart of the ABS system consists of a control module in a pump which is one component.ABS components also consist of brake lines, brake calipers and wheel speed sensors. Each wheel has its own wheel speed sensor which has a permanent magnet which generates AC voltage by means of an air gap and a toothed ring also called a tone wheel. The faster the toothed ring turns with the vehicles wheel the more voltage the wheel speed sensor generates which provides wheel speed information to the control module.
ABS warning light is commonly due to a wheel speed sensor not receiving the proper voltage. Dirty from rust and debris causing air gap issues or because it’s worn out and needs to be replaced.A toothed right that’s rusted,damaged,cracked or has missing teeth is also a common cause.
This post will show you how to use Launch Creader v to diagnostic Toyota vehicle when the vehicle get a ABS warning light on the dashboard.
Procedure:
Driving the car and using a diagnostic scanner to check the live data from all four wheel speed sensors.
Noticed the right rear wheel speed sensor shows nothing.
Connect Launch Creader VII+, press “Diagnose”
After diagnosis, we get trouble code C1332 which says open circuit in right rear wheel speed sensor circuit.
Disconnect the electrical connection to the wheel speed sensor
Turn the ignition key to the “ON” position, do not start the vehicle
Check the electrical connections with a digital multimeter. Set on DC volts
Get voltage value “3.62”
Check the voltage on the left rear side and get voltage value “4.75”
Obviously,the right side is not getting enough voltage. Turn ignition to the “OFF”
Removed the rear seat to access to the wheel speed sensor cable connection.
Check the end of this cable which goes to the wheel speed sensor for continuity.
Attach the probe to one side of the wheel sensor cable
Check the other end of the cable with the other probe
Same test to the other side.
After checking, we know there is no continuity on the left side. That means the cables bad and needs to be replaced.
Replace the old cable
Erase the code
Start the vehicle, there’s no ABS light show anymore.
More repairing cases of Toyota, please click here: Toyota Repair.