This function is used to confirm that the ECU can read the signals from the speed sensors and to exclude faults such as: Demagnetized ABS-ring gears, too big gap between sensor ring gear and wheel sensor, damaged hub, incorrectly installed/connected sensors.
Note:
The function is used after work on:
Wheel bearings.
Hubs.
Ring gear.
Wheel speed sensor.
Test conditions:
Engine off.
Ignition on.
Parking brake released.
Vehicle raised so that the wheels can rotate freely.
Procedure:
Start the function.
Select the wheel to be tested.
Press "Start".
Rotate the wheel exactly one revolution. Make a mark on the wheel and the body, for example.
Press "Stop".
The result is shown. Should be approx. 60 pins +/-1.
Repeat the procedure from step 2 to test the other wheels.
The function is done.
If the function fails, check the test conditions and repair any faults.