Hi all,
I think the suspension in my Xantia Exclusive is defaulting to hard mode. I know this is a problem in XMs (Mine had had the Wolsey House permanent soft mod done to hide it until Jim Eastment rectified it for me). Do the Xantia Hydractive ECUs also fail in the same way?
If they do, can you please advise as to a solution? Or does anyone in the Cambs/Northants area have a spare ECU I could try in order to rule it out?
Symptoms: My car's ride feels a shade fidgety compared to non Hydractive Xantias I've driven - not bad by normal standards but it feels like something isn't right. I'm running correct tyre pressures, and all the spheres were replaced by IFHS spheres ordered to the car spec two years ago. I can't detect a difference when I select sport mode on the Hydractive switch.
Xantia HDi Exclusive Hydractive hard
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admiral51
- (Donor 2026)
- Posts: 2681
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Re: Xantia HDi Exclusive Hydractive hard
The default mode for the Xantia Hydractive is hard mode if the fuse is pulled/blown or the electrovalves are duff.
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white exec
- Posts: 7445
- Joined: 21 Dec 2015, 12:46
- x 1751
Re: Xantia HDi Exclusive Hydractive hard
Hi Sam,
The Sport switch will not put the system immediately into Firm mode - that was how the original Hydractive (Hydractive 1) system worked. For Hydractive 2 (which is what Hydractive Xantia and later XM have), manually selecting Sport simply modifies the thresholds (throttle position, steering movement, body movement) when the system flips into Firm. The effect is for the car to go Firm much more readily. Parked (engine running) or driving at less than c.20km/h, the system should always be Soft.
You will need to check that the front and rear suspension electrovalves (EVs) and both being powered, and switching.
Powered EVs = soft
EVs off = firm
Bounce test:
- With car parked, start engine and let car assume normal running height.
- Switch engine off, close doors, and listen for a buzzing sound under the car, coming from both front and back. This should stop with an audible click after 30secs. This is the EVs switching off.
- When they switch off, try pushing down on the rear of the car, and at the front. Both should feel pretty much solid, no easy give. This is Firm state (EVs off).
- Open a door, and you should hear the buzzing start again. The car goes into Soft when a door is opened.
- With/without starting the engine, press down again on rear end, and there should be noticeably move 'give'. More movement at the front, too, but less than the rear. This is the powered EVs switching the car into Soft.
That test should show up whether the system is capable of both Soft and Firm.
Firm ride is provided by the four corner spheres working on their own.
Soft ride comes ONLY from the centre (Hydractive) spheres also being in circuit, switched in by the EVs acting on the hydraulic regulators they are mounted on.
Unlikely that the suspension ECU has failed, but worth checking the supply/fuse to it, and that the black and white 15-way connectors to it are clean. An ECU or system/sensor fault will be flagged by the dash Suspension light either remaining on (in Normal mode) or flashing. (The ECU not only checks itself when the IGN is switched on, but also the connected sensors - however, it only checks the EVs presence, not whether they are operating correctly.)
EV failure happens, usually the small diode encapsulated in each one. To remedy this (or to sidestep future failure) an additional diode is often added to each EV supply line, as backup. Working diodes are essential for the correct operation of the EVs, and to protect the ECU from spikes when the EVs switch off.
Try the test, and let us know what you find.
Caution: Do not allow 12v to be applied directly to either EV, even for test purposes, as they can be irreparably damaged.
The Sport switch will not put the system immediately into Firm mode - that was how the original Hydractive (Hydractive 1) system worked. For Hydractive 2 (which is what Hydractive Xantia and later XM have), manually selecting Sport simply modifies the thresholds (throttle position, steering movement, body movement) when the system flips into Firm. The effect is for the car to go Firm much more readily. Parked (engine running) or driving at less than c.20km/h, the system should always be Soft.
You will need to check that the front and rear suspension electrovalves (EVs) and both being powered, and switching.
Powered EVs = soft
EVs off = firm
Bounce test:
- With car parked, start engine and let car assume normal running height.
- Switch engine off, close doors, and listen for a buzzing sound under the car, coming from both front and back. This should stop with an audible click after 30secs. This is the EVs switching off.
- When they switch off, try pushing down on the rear of the car, and at the front. Both should feel pretty much solid, no easy give. This is Firm state (EVs off).
- Open a door, and you should hear the buzzing start again. The car goes into Soft when a door is opened.
- With/without starting the engine, press down again on rear end, and there should be noticeably move 'give'. More movement at the front, too, but less than the rear. This is the powered EVs switching the car into Soft.
That test should show up whether the system is capable of both Soft and Firm.
Firm ride is provided by the four corner spheres working on their own.
Soft ride comes ONLY from the centre (Hydractive) spheres also being in circuit, switched in by the EVs acting on the hydraulic regulators they are mounted on.
Unlikely that the suspension ECU has failed, but worth checking the supply/fuse to it, and that the black and white 15-way connectors to it are clean. An ECU or system/sensor fault will be flagged by the dash Suspension light either remaining on (in Normal mode) or flashing. (The ECU not only checks itself when the IGN is switched on, but also the connected sensors - however, it only checks the EVs presence, not whether they are operating correctly.)
EV failure happens, usually the small diode encapsulated in each one. To remedy this (or to sidestep future failure) an additional diode is often added to each EV supply line, as backup. Working diodes are essential for the correct operation of the EVs, and to protect the ECU from spikes when the EVs switch off.
Try the test, and let us know what you find.
Caution: Do not allow 12v to be applied directly to either EV, even for test purposes, as they can be irreparably damaged.
Chris
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Sam Skelton
- Posts: 15
- Joined: 03 Nov 2015, 11:30
Re: Xantia HDi Exclusive Hydractive hard
Thanks Chris.
My electrovalves would appear to be working. I can't hear the buzzing but the car definitely stiffens when off and left, and softens when doors are opened/turned on.
Out here in the Fens given the road surfaces I'd expect to feel a near immediate difference in the car's behaviour, even though I know H2 isn't a direct "sport" mode - I understand it works like my XM, and that understanding combined with the broadly similar pressurisation of the spheres is why I'm disappointed in the ride. It's not as good as my XM by some margin, nor is it as good as non Hydractive Xantias I've owned and experienced. If there's nothing clearly wrong with it I'll have to chuck it at a specialist or expert, but I'd rather try and chase it down myself if I can.
The Hydractive fuse is fine, I haven't checked the connector yet.
My electrovalves would appear to be working. I can't hear the buzzing but the car definitely stiffens when off and left, and softens when doors are opened/turned on.
Out here in the Fens given the road surfaces I'd expect to feel a near immediate difference in the car's behaviour, even though I know H2 isn't a direct "sport" mode - I understand it works like my XM, and that understanding combined with the broadly similar pressurisation of the spheres is why I'm disappointed in the ride. It's not as good as my XM by some margin, nor is it as good as non Hydractive Xantias I've owned and experienced. If there's nothing clearly wrong with it I'll have to chuck it at a specialist or expert, but I'd rather try and chase it down myself if I can.
The Hydractive fuse is fine, I haven't checked the connector yet.
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white exec
- Posts: 7445
- Joined: 21 Dec 2015, 12:46
- x 1751
Re: Xantia HDi Exclusive Hydractive hard
Sounds as if the system is switching between Soft and Firm.
Xantia is a firmer ride than XM, and non-Hydractive cars (except the sporty versions) tend to be softer sprung than Hydractive ones. When Hydractive first appeared, the firmer ride was noted, even though it was probably part of a general drift towards a firmer ride by Citroen.
Are the spheres exactly the correct ones (i.e. correct damping) and at the correct gas pressure, even though they're not very old? If you're going to keep the car, then fitting some Tecnosir Valprex regassing valves might be an idea, as it allows gas pressure to be checked (eg every 2-3 years), as well as topping up. This can keep decent spheres going for years. You could do the XM as well.
Xantia is a firmer ride than XM, and non-Hydractive cars (except the sporty versions) tend to be softer sprung than Hydractive ones. When Hydractive first appeared, the firmer ride was noted, even though it was probably part of a general drift towards a firmer ride by Citroen.
Are the spheres exactly the correct ones (i.e. correct damping) and at the correct gas pressure, even though they're not very old? If you're going to keep the car, then fitting some Tecnosir Valprex regassing valves might be an idea, as it allows gas pressure to be checked (eg every 2-3 years), as well as topping up. This can keep decent spheres going for years. You could do the XM as well.
Chris