Discovery II
FRONT SUSPENSION
60-20
DESCRIPTION AND OPERATION
Failure modes
Failures where the vehicle can still be driven safely are indicated by the ACE warning lamp illuminating continuously
with an amber colour. The amber warning lamp will remain illuminated until the ignition is turned off. For all faults the
warning lamp will only illuminate again if the fault is still present. Failures which require the driver to stop the vehicle
immediately are indicated by the ACE warning lamp flashing with a red colour and an audible warning. All faults are
recorded by the ACE ECU and can be retrieved with diagnostic equipment.
The following tables show the type of system failures and their effects on the system operation. Torsion bar 'floppy'
means that fluid is allowed to circulate freely through the system. With no pressure in the actuators the torsion bar will
have no effect on vehicle roll. 'Locked bars' means that all pump flow is directed through the valve block and returns
to the reservoir. Both DCV's close and fluid is trapped in the actuators but can flow from one actuator to the other via
the valve block. In this condition the torsion bar will perform similar to a conventional anti-roll bar, resisting roll but still
allowing the axles to articulate.
Acceleration sensors
Pressure transducer
Road speed signal
21
Pressure transducer (earth)
Input
22
DCV 2 (earth)
Input
23
DCV 1 (earth)
Input
24
DCV 1 & 2 (supply)
Output
25
Pressure control valve (earth)
Input
26
Not used
-
27
Pressure control valve (supply)
Output
28
Main supply (+ V Batt)
Input
29 to 31
Not used
-
32
Main earth 2
-
33
Accelerometer - lower (signal)
Input
34
Accelerometer - upper (signal)
Input
35
Not used
-
36
Warning lamp
Output
Failure
Effect
Valve stuck closed
No ACE control
Short circuit - Ground
No ACE control
Short circuit - VBatt
No ACE control
Loose sensor
Erractic ACE activity when driving in straight line
Failure
Effect
Short circuit - VBatt
Large sensor dead band - possible random
movements
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
Pin No.
Description
Input/Output