Wiring Diagram Practice

Wheel Speed Sensors:
Front Right - Black & White
Front Left - Green & Red
Rear Left - Blue & Pink
Rear Right - Brown & Yellow




The reason for braided wire:
In the ABS System braided wire is used. This is to prevent external interference with the ABS signals. Being a safety feature it is extremely important that the signals are kept clear, as even the smallest of signal interferences at the wrong time could be fatal.

List of fuses used by the ABS circuit:
50A ABS, 10A gauge, 20A done, 15A stop, 15A ECU-16

Identify the Earths for the ABS control unit and ABS motor:
ON - A17-A A18-B
GND 10/GND 7

On the wiring diagram for the ABS actuator, identify which solenoids control which wheel cylinder. Note the wire colours and pin numbers.

Front Right Wheel - Pin Number: 2B
- Wire Colour: Red/white

Front Left Wheel - Pin Number: 3B
- Wire Colour: Blue/Red

Rear Left Wheel - Pin Number: 1B
- Wire Colour: Brown/White

Rear Right Wheel - Pin Number: 4B
- Wire Colour: Green/Black




Using the picture above as a guide, Identify what the Inlet and Outlet Solenoid Valves are doing at certain Braking conditions:

1. Under normal braking conditions the Inlet solenoid valve is Open, and the Outlet valve is Closed.
2. When the ABS is operating to reduce wheel brake pressure the Inlet valve is Closed and the Outlet valve is Open.
3. When the ABS is operating to hold brake pressure, the Inlet valve is Closed and Outlet valve is Closed.
4. When the ABS is operating to increase wheel brake pressure, the Inlet valve is Open, and Outlet valve is also Open.

The ABS Motor will operate in condition numbers 2, 3 and 4 above.


This graph shows a digital signal swithcing 5v every 2 seconds.


This graph shows an analogue signal with a frequency of 0.5 Hz and a maximum of +3v.