Diagnostics (page 2 of 2)

BRAKES

70-18

DESCRIPTION AND OPERATION

Checks Performed By Diagnostics

Fault

Status of Warning Lamps

Default Strategy

ABS

ETC

HDC 

Fault

HDC Information

ABS ECU internal failure

On

On

On

Off

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

ECM input failure

Off

On

On

Off*

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

Sticking throttle

Off

Off

On

Off*

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

Implausible gear position 
input

Off

Off

On

Off*

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

No reference earth

On

On

On

Off

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

Failure of ABS sensor

On

On

On

Off†

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

Failure of 2 ABS sensors

On

On

On

Off*

ABS: Enabled on unaffected hydraulic 
circuit (if applicable), disabled on 
affected hydraulic circuit(s).
ETC: Disabled.
HDC: Immediately disabled if not in 
active braking mode, faded out then 
disabled if in braking mode.

Failure of more than 2 
ABS sensors

On

On

On

Off

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

Failure of input valve

On

On

On

Off

ABS: Enabled on unaffected hydraulic 
circuit (if applicable), disabled on 
affected hydraulic circuit(s).
ETC: Disabled.
HDC: Immediately disabled if not in 
active braking mode, faded out then 
disabled if in braking mode.

Failure of more than one 
input valve

On

On

On

Off*

ABS: Enabled on unaffected hydraulic 
circuit (if applicable), disabled on 
affected hydraulic circuit(s).
ETC: Disabled.
HDC: Immediately disabled if not in 
active braking mode, faded out then 
disabled if in braking mode.