Front Suspension - ACE Description for Discovery II
FRONT SUSPENSION
DESCRIPTION AND OPERATION
60-21
Engine speed signal
Reverse gear signal
Ignition ON signal
Pressure control valve failure
Directional control valves
Failure
Effect
Open circuit
No ACE control - 'Locked bars' condition
Short circuit - Ground
No ACE control - 'Locked bars' condition
Short circuit - VBatt
No ACE control - 'Locked bars' condition
Failure
Effect
Open circuit
No reverse signal to ECU. ACE active in reverse,
may give abnormal handling when reversing
Short circuit - Ground
No reverse signal to ECU. ACE active in reverse,
may give abnormal handling when reversing
Short circuit - VBatt
Permanent reverse signal to ECU. Permanent
'Locked bars' condition
Failure
Effect
Open circuit
ECU does not receive ignition ON signal. No ARC
control, 'Locked bars' condition
Short circuit - Ground
ECU does not receive ignition ON signal. No ARC
control, 'Locked bars' condition
Short circuit - VBatt
Permanent ignition ON signal to ECU. Possibility of
flat battery
Failure
Effect
Open circuit
No ACE control
Short circuit - Ground
No ACE control
Short circuit - VBatt
No ACE control
Valve stuck open
No ACE control
Valve stuck closed
Maximum system pressure - no proportional control.
Pressure relief valve operating at 185 bar (2683
lbf.in
2
)
Failure
Effect
DCV 1
DCV 2
Valve open or stuck open Valve open or stuck open No ACE control - Anti-roll bars floppy
Valve closed or stuck
closed
Valve closed stuck
closed
No ACE control - 'Locked bars' condition (default)
Valve open or stuck open Valve closed or stuck
closed
Vehicle leans to left when pressure is applied to
actuators
Valve closed or stuck
closed
Valve open or stuck open Vehicle leans to right when pressure is applied to
actuators
