I can't find any info on the active suspension height system, not even in the service manuals in this website. Can anyone advise/help please?
Sorry it is an 04 manual diesel amazon 100
Neil
I'm looking for info on this as well as I'm trying to understand the system on my 2001 'VX'. The 'Expert' appears to be 'uHu' in Norway, hopefully he'll pop in.
Why are you replacing the struts ??
My understanding is that the struts are just that - they contain the AHC fluid which is pumped in to make them longer or let out to let the car settle.
Fluid, from the pump assembly under the bonnet, passes through an 'Actuator' mounted on the chassis alongside each strut. The rate at which fluid is allowed to pass in and out of the strut is controlled by this Actuator - which gives the necessary damping.
Fluid can't be compressed, so on the other end of each 'Actuator' is a sphere (or Globe) which contains a diaphragm with compressed gas on the inside. As the suspension moves, the fluid from the strut is pushed through the Actuator and into the Globe, compressing the gas. This gives the suspension travel.
The height of the suspension is controlled by the AHC ECU which gets its readings from the three 'Height Sensors' (one at each side at the front and a single one above the rear axle).
So. Height is set by the switch in the car which causes the pump to pressurise the system (going up) or release fluid back into the reservoir (going down). All managed by the ECU which is watching the Height Sensors.
Ride characteristics (Comfort, Sport) alters the Compression Damping at each Actuator. I'm not sure whether Rebound Damping is affected - probably.
Suspension Travel is determined by the gas in the Globes . . . Which is where we get problems.
The Globes can lose their gas with age. When this happens everything else continues to work but instead of pressurising the gas, the globes fill with fluid. You have the same Ride Height as before but there will be a lot less fluid in the reservoir under the bonnet and the suspension will be rock hard.
This may, of course, only affect one corner - or any combination of the four
.
I don't know the procedure for replacing any one item in this assembly, but I expect it to be messy. Looking at the underside of mine (which has had 13 years of Northern road salt) I can't imagine anything coming apart cleanly.
So back to my first question - why are you wanting to replace something ??
(If 'uHu' can come along and correct my understanding I'll be very grateful
).
Bob.