How to test the Activa System?

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CitroJim
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How to test the Activa System?

Post by CitroJim »

Apart from hacking around sweeping tight bends at insane speeds or making a spectacle or yourself going round and around a roundabout at silly speeds, is there any accepted way of conducting a test of the Activa System with the car at a standstill in a similar way to which the Hydractive system can be tested?

I'm after a method to determine if the Activa Spheres are in reasonable health without having to remove and pressure test them and also to determine if the Activa Electrovalve is working as it should.

I should say that mine seems to pass the sweeping bend test and the roundabout test but it's not a very scientific test...
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Post by Mandrake »

Pressure testing is probably your best bet I'm afraid, with a system that complex and that many spheres it would be hard pinpointing a specific symptom to a given sphere...

Having said that, going by the theory of operation (and never having driven one) - the front Activa sphere (on the gearbox with the pipe coming out) is a seperate accumulator which supplies the Activa system to make sure there is always a supply of instant pressure to make a correction - and if that sphere was flat I would imagine the symptom would be that the system was no longer fast enough to make "instant" corrections to the body roll, and that if you did some quick zig zaggy stuff you would get delays in the correction and the car wouldn't corner flat.

If you can chuck it left and right back and forth quickly and it seems to stay flat without any discrete roll-correct actions I'd say that sphere is probably ok.

The rear Activa sphere is the one that "softens" the rollbar stiffness during normal driving. (Both rear AND front rollbars) If that one was flat (or wasn't being switched in) you'd have the stiff rollbar mode all the time, the probable symptom of that is that on roads that have random left right leans in the gradient, the car would tend to rock left and right with those leans rather than try to absorb it.

Trouble is, the front sticking in Hydractive hard mode has that kind of effect too (as you probably noticed) so telling them apart could be difficult.

Not too sure what else to suggest...

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Simon
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Post by CitroJim »

Thanks Simon,

That has been a great help. You have identified which Activa Sphere is which for me and after reading the theroy many, many times I could not work out which was which. 8)

It flat-corners a treat, does not do anything funny so I guess its good. I only realise just how well it does its thing when I jump in and drive the SX TD or the 205D. It rolls a little less than my 205GTi so on that basis...

Thanks, by the way, for your HA Electrovalve posts. They helped me enormously in sorting out why the front stayed in hard mode all the time :D
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
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