BRAKES: DESCRIPTION AND OPERATION (page 5 of 5)

BRAKES

70-24

DESCRIPTION AND OPERATION

Default strategies

Electrical data
Nominal resistance values for applicable brake control components are as detailed below:

Fault

Default strategy

Brake lamps relay

ABS: Enabled.
ETC: Enabled.
EBD: Enabled.
HDC: Enabled.

Throttle position signal failure

ABS: Enabled.
ETC: Disabled.
EBD: Enabled.
HDC: Immediately disabled if not in active braking mode; faded out then disabled if in active 
braking mode.

No reference earth

ABS: Disabled.
ETC: Disabled.
EBD: Partly disabled.
HDC: Disabled.

Return pump or relay fault

ABS: Disabled.
ETC: Disabled.
EBD: Partly disabled.
HDC: Disabled.

Shuttle valve switch failure

ABS: Deceleration threshold increased; return pump activated if sum of output valve 
actuation on one axle exceeds 140 milliseconds.
ETC: Disabled.
EBD: Inlet valves of rear axle close at vehicle deceleration rates of  0.3 g and above.
HDC: Disabled.

SLABS ECU internal failure

ABS: Disabled.
ETC: Disabled.
EBD: Disabled.
HDC: Disabled.

Supply voltage out of limits

ABS: Disabled.
ETC: Disabled.
EBD: Disabled.
HDC: Disabled.

Component

Resistance, ohms

Brake lamp relay coil

117 - 143

Return pump relay coil

82.8 - 101.2

ABS sensor

950 - 1100

Shuttle valve switches, both open (brakes off)

2977 - 3067

Shuttle valve switches, both closed (brakes on)

1007 - 1037

Shuttle valve switches, one open, one closed

1992 - 2052

Inlet solenoid valve

5.9 - 7.3

Outlet solenoid valve

3.0 - 3.6