4

4

Graphs

1) On the graph below draw a digital signal that switches 5 volts every 2 seconds.
Mark volt and time scales on graph that will show the signal well.

Wiring Diagram Practice

1)identify the wheel speed sensors and list their
wire colours for each sensor

LEFT FRONT=black & white
FRONT LEFT=RED & GREEN
REAR LEFT=BLUE & PINK
REAR RIGHT=YELLOW & BROWN

2)On the ABS wheel sensor what is the reason for the braded wire? Prevent interference from other singnals that the sensor may pick up

3)Identify and list all the fuses that are used by the ABS circuit? 17 3a, f14, 19

4)Identify the earths for the ABS control unit and ABS motor their wire colours what pins numbers? pin numbers (10b,7b,1a)

5)On the wiring diagram for the ABS actuator, identify which solenoids control which wheel cylinder.
Front Right Wheel= pin 5B, wire colour red & blue
Front Left Wheel= pin 1A, wire colour red & blue
Rear Left Wheel= pin 12B, wire colour brown & white
Rear Right Wheel = pin 15A, wire colour green & yellow

6)Using the picture on the next page as a guide, which of the following gives the correct condition of
the inlet and outlet solenoids valves under normal braking?

A: _false___ Inlet valve Open Outlet valve Open
B: _false___ Inlet valve Open Outlet valve Closed
C: _false___ Inlet valve Closed Outlet valve Open
D: _false___ Inlet valve Closed Outlet valve Closed

7)Using the picture on the next page as a guide, which of the following gives the correct condition of
the inlet and outlet solenoids valves when the ABS is operating to reduce wheel brake pressure?

A:_false___ Inlet valve Open Outlet valve Open
B:_false___ Inlet valve Open Outlet valve Closed
C:_true___Inlet valve Closed Outlet valve Open
D: _false___ Inlet valve Closed Outlet valve Closed

8)Using the picture as a guide, which of the following gives the correct condition of the inlet and outlet
solenoids valves when the ABS is operating to hold brake pressure?

A:_true___ Inlet valve Open Outlet valve Open
B:_false___ Inlet valve Open Outlet valve Close
C:_false___ Inlet valve Closed Outlet valve Open
D:_true___ Inlet valve Closed Outlet valve Closed

9)Using the picture as a guide, which of the following gives the correct condition of the inlet and outlet
solenoids valves when the ABS is operating to increase wheel brake pressure?

A:_false___ Inlet valve Open Outlet valve Open
B:_true___ Inlet valve Open Outlet valve Closed
C:_true___ Inlet valve Closed Outlet valve Open
D:_X__ Inlet valve Closed Outlet valve Closed

10)he four cases above state when the ABS motor will be working? increased pressure

ABS Wiring and Operation

1= discs
2= wheel sensor
3= tone wheel
4= hydralic control unit
5= master cylinder

6= Callipers

7= brake booster

Off-car Exercises
Think about ABS Repair:

Spiked by careless welding, i.e. MIG welding without disconnecting the battery.=True

Enclosure seal damaged and with obvious sign of water ingress.=true

Obvious signs of mechanical damage to the enclosure.=false

Faults are much more likely to be with connections or sensors.=True