ABS (anti-lock braking system for RHD)

Wiring diagram practice

using the wiring diagram identify the wheel speed sensor's wire colours:
-front right= White + Black
-front left= Green + Red
-rear left= Pink + Blue
-rear right= Broen + yellow

The reason for the braded wire on the ABS wheel sensor is to stop interferance and it sheilds the wires from frequency.

identify and list all the fuses that are used by the ABS circuit:
-ignition fuse
-warning light fuse
-stop light fuse
-ABS fuse

Earths for the ABS control unit and ABS motor, wires and pins :
-pin-10  White/black
-pin-7  White/Black

identify which solenoids control each wheel cylinder, wire colours and pin numbers:
-Front right: Pin-6a        wire colour-red white
-Front left wheel:  pin numbers-3B,7B          wire colour- Blue/red and Blue/white
-rear left wheel:  Pin numbers-1B and 5B      wire colour-Brown/red and Brown/white

In four cases stae when the ABS motor will be working?
-when the wheels lock up
-when the wheels spin abnormally fast
-when the brake is suddenly applied
-when under or over steer happens

ABS demonstrators
Left front      ECU pin#   4 and 5
Left rear       ECU pin#  7 and 9
Right front    ECU pin#  11 and 21
Right rear     ECU pin#   24   and  26

By looking at the wiring diagram i could tell that the sensors were magnetic inducer type sensors
How it works:
A passing magnet induces a current through the windings and it has a magnet that increases the magnetic field in the windings.

next i grabed a set up ABS module and hooked up a occiloscope and recorded a waveform for the front right sensor...

The waveform for the front left and the back left were the same and the front right and back right were both the same but both right sensors had a higher peak voltage than the left ones.

with the wheel speed sensors spinning, measure AC volts with a multi-meter and record the voltages (RMS):

left front  3.593V

left rear   2.696V

right front  4.473V

right rear   5.14V

this is not an accurate way to find problems compared to and oscilloscope

An oscilloscope is better to find problems with the wheel speed sensors than a multi-meter because an oscilloscope measures and records waveforms which can show peak voltages and frequencies whereas a muti-meter cannot.