Spent hours on this yesterday with vcds ,on further investigation I did think the car sat a little low ,specs for se are 415mm front and 400mm rear ,centre hub to wheel arch ......well to be precise it's 416mm front and 398mm but a couple of mm is hear na there ,mine was sitting at 380mm font 375 rear .
Tried removing battery lead again and a bit of driving round ( will get back to this ! ) , in dynamic mode it was terrible ...... May aswell of been dragged around on a shovel !
Coding of level control the double 5 meaning 0 change from base
Where I was getting a bit lost the double 55 being base I would of thought that in the calibration the desired height would of been 416 f and 398 r but it was not , can't remember what but it was a lower setting , so thought need to get it up to standard ride height so the air bags are at there optimum for a comfort ride , so changed the code to 99 + 20mm , this change got it to nearly factory spec ride height .
So test drive at standard ride height ...... it's better for sure but still not as silky smooth as before , I digress .....I took laptop with me on test drive and in comfort mode damping was showing in data blocks as 1.8 amps ... max amps =soft damping , min amps 0.2 amps or some such hard damping setting
When stood still damping is at hard setting , as you get above 10 mph damping reverts to softest setting but watching it on test drive it going from on extreme to the other 0.2 amp ... 1.8 amp sort of cycling effect ..... mmmmm
I was looking through the data and spotted this .....
As soon as I saw this I new what was wrong .... strut velocity ..... Eureka !!!
500 SL Mercs with hydractive advance body control suspension have similar .... I've done quite a bit of work on these , they have something called strut measurement rod , it runs through the middle of the strut and measures how it is reacting on the road , if the body battery ever goes flat the damping defaults to a hard setting .
You have to drive them in sport mode ( the hardest damping ) for a good 10 miles or more and the suspension ecm learns how the strut is reacting and dials the damping in , once sport is learned the comfort mode is just a softer map of that .
Are you still here or lost interest and gone to watch the paint drying ........
Back to the a8 ........ so in dynamic mode I set off on test drive maybe after 10 miles of shaking the fillings out of my teeth it starts to get a bit more plush on the ride .... keep driving .... it's getting better by far , switch over to comfort now ...... the plush ride is back to normal ...... it's the ecm learning the strut velocity and dialling it in to the damping map .
Still unsure with the ride height thing , don't understand why the double 5 coding is not the spec ride height , it looks a bit high now so will try it back at that setting .
In reflection I reckon if I just drive the car around in dynamic after I had the battery off everything would of sorted it's self out on its own ..... that's adaptive drive cycle for ya
What I think has happened originally , I had a shunt across the battery doing testing on how much amps is drawn when auxillary hearing kicks in , I was sort of mucking about trying to get a good contact so the battery was kind of connected then not then connected then not , it must of just upset the modules somewhat and defaulted it to safe , because I have had the battery off before with no adverse effects .
A battery shunt is a device that allows you to go inbetween the heavy cable so you can 'tap off ' and measure amps draw without blowing your multimeter all the time ..... just for those who was wondering don't cha know
Hard work typing all that on an iPhone ....... frekkin predictive text .... a tell thee ..