11-26-2021, 07:33 AM | #1 |
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Many of you know I have had issues with the car and my Variable Damper system. This has been going on for 11 months. I knew a week after buying the car that something was off, it just didn't feel like a BMW and had vibrations and instability in the rear especially. The seller helped me with cost at BMW for 6 months but as they kept saying no issue he eventually stopped once I was outside his warranty (we didn't fall out over this) I bought ISTA and a cable and investigated myself while learning all about the cars system. I changed items that BMW told me to (totally waste as the alloys and tyres were not the issue as I suspected) or that I felt were the issue. In summary don't let BMW try solving a VDC issue as they haven't a clue how it works and tend to just blame tiny buckles or tyres or tracking or anything else. They didn't even check the VDP module as standard. Other issue is no fault codes are kicked for malfunctioning VDP or ACSMs. The ACSM is a very sneaky piece of kit, seems it is noted as only to do with the air bags etc, but it also had the huge job of controlling the entire flex ray system and all sensor feeds to every module in the car, hence if it malfunctions it can cause all sort of issues. I'm convinced BMW messed up my VDP and ACSM when I had them do a full IStep software update a week after purchase. Thank the gods for KUBAX on here he was the person who helped me change the VDP recode it and recode my ACSM today which finally has the car fixed. Next steps are to get it remapped and ceramic coated as I wasn't willing to do either until I fixed the Variable Damper issue. For anyone interested to date in sequence with cost in euros Car unstable ride in town over uneven surface • Refurbished alloys (500) • Changed tyres non-RF (1170) • New alloys and tyres with RF (3600) (old alloys were 759Is and had manufacturing defect BMW refused claim as I refurbished them but only because BMW had dented one of them go figure) • RFB on alloys (100) • Changed tyres to MPS4S (1200) • Multiple trailing arms and rear subframe inspections incl. RSF bolts replaced by BMW (500) Vibration on highway now added to unstable in town • RFB on tyres (100) • Changed VDC cable front left (50) • Changed VDC shock front left with used one (350) Noticed that VDP voltage was 6ma to front left and all other zero makes no sense • Changed VDP module and had coded (300) Most of instability gone vibration remains and all shocks get 2 ma but front left gets 3 ma. • Changed back to original tyres (100) • RFB on tyres (100) Vibrations gone was related to the MPS4S tyres being defective but seems like one shock rear right feels harder than all others in town and front left gets 3ma still. • Michelin refunded me to a credit note at BMW (1170) • Changed rear ARB drop links (220) • Changed rear left bearing (200) Scoped all shocks while driving over bumps seems they are fluctuating wildly when going slow, video on you tube. Higher amps = harder shocks. 2ma seem to be rest state but changes in Ma don't correlate to the shock that hits a bump. Decided to have ACSM recoded and VDP (100) FINALLY FIXED:: So spent Euro 8590 and received Michelin credit back to BMW at 1170 total = EURO 7420 If BMW had identified the issue, it would have cost me for new alloys and tyres and a new VDP plus ACSM and VDP coding = EURO 4100 Wasted Euro - 3320 because of BMWs inability to understand their own cars and refusal to properly diagnose even when told to do so and paid. ACSM recode solved the issue thank the gods and Kubax!!! |
11-26-2021, 12:21 PM | #2 |
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So recoding the air bag module helped with random road vibration/harmonics? I've gotten more and more annoyed by it lately as my work commute is 90% highway where its really noticeable.
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11-26-2021, 01:26 PM | #3 |
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Yep helped vibrations and rear instability.
The variable dampers also work to reduce vibrations so if they are not working properly it can cause the issue. It's all down to how the sensor data is shared and the ACSM manages that via flex ray. Well worth a try to recode your ACSM and VDP as kubax charges very little for his work compare to what BMW charge for their time. Even if it doesn't solve it it's small money. All you need is a cable and your laptop and communicate with the car he then logs in remotely. My main fix was a recoded VDP that runs the variable dampers and a recoded ACSM as it was clearly corrupted. |
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11-26-2021, 01:40 PM | #4 |
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Mach550 any chance your running Michelin pilot sport 4S tyres?
If so then that's likely your issue as it was causing harmonic vibrations on my car. I went up a side wall size as I see you planned on other threads and the PS4S caused vibrations on the motorway that rise and fall. |
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11-26-2021, 01:45 PM | #5 |
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FYI Michelin refunded me (took 3 months) when I priced it was the tyres by using vibration analysis tools and when it immediately went away after swapping.
In US you have much better warranty from Michelin than here where I had to wait months. See below the NVH app the brown line is the harmonic vibrations caused by the over size sidewall MPS4S tyres. |
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11-26-2021, 04:01 PM | #7 |
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Looks interesting are you using it? Would like to know how easy it is to use.
Does the phone have to be permanently attached or can you upload a remap and then come back later and change back to stock. Looks like it's around $425 for licence and a stage 2 map for the B48 engine. Can probably get BMWorkshop to do it for that price in Rathcoole. https://www.bmworkshop.ie BMW are useless these days in Ireland, I couldn't be bothered with them knowing even if the engine blew as they won't offer any good will since the UK office took charge but I would like to be able to revert if selling. QUOTE=IrishG30Guy;28297553]Have a look at MG flasher if your thinking of remapping.[/QUOTE] |
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11-26-2021, 10:52 PM | #8 |
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Glad you finally were able to wrestle this to submission!
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11-27-2021, 05:50 AM | #10 |
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Thanks guys and a huge thanks for everyone's advice and feedback over last 11 months was a hill to climb.
Good thing is I'm probably the resident expert on VDC for 530e's so if anyone has any problems in future I'm available. Never let a machine get the better of you!!! |
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11-29-2021, 06:19 PM | #11 |
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After last few days working I have to say the VDC is sublime when it works.
I'm gonna have to go find any posts I made last few month complaining about it and change my opinion. It really is a huge improvement over non VDC with 20s which I have driven a few of recently. |
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11-30-2021, 03:49 AM | #12 | |
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What has surprised me, it didn't throw up a code or two on your car, when malfunctioning. I also wonder if any dealers in the UK would have suggested a VDC fault, due to your symptoms. |
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02-27-2022, 08:44 PM | #13 |
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my G30 530i with VDP got the same issue, thank you and I'm planning to recode my acsm and vdp modules for a try.
And I also wonder whether the standstill amp of the four wheels will be different after replace the VDP module. now my standstill amp is FL:0ma, FR:4ma, RL:0ma, RR:0ma, I'm not sure if the value to be exactly 0 is what it should be . Last edited by X-skyer; 02-27-2022 at 08:56 PM.. |
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02-28-2022, 01:46 AM | #14 |
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All should give a current;
https://g30.bimmerpost.com/forums/sh....php?t=1841950 |
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02-28-2022, 08:56 PM | #17 |
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This whole thread has convinced me that I don't have the appetite for VDP. I bet it's awesome, but that kind of headache gives me nightmares. I believe a good friend of mine has something similar on his Mercedes GLS and the Benz dealer didn't know how to fix theirs either. Took him 2-3 months to get it right.
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01-06-2023, 03:04 PM | #18 | |
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I have an i4 M50 and have experienced vibration/instabilities last 6 months. I did a read out from the VDP module which resulted in RL 0mA, RR 0mA, FL 6mA and FR 0mA at standstill. Just to confirm before I head back to the dealer with my findings - can I trust these values or could I potentially have done something wrong in ISTA when pulling these values? Also, since you recoded the ACSM module as well, was there anything in ISTA that indicated problems with this module? Thanks. |
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01-08-2023, 12:39 PM | #19 |
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Hi your VDP reading are correct it’s just interrogating the voltages via the VDP you can’t get it wrong with ISTA but you do 100% have an issue as they should all show voltage all the time even at standstill.
Sounds similar to my issue I had the VDP replaced and recoded but I suspect recoding alone would have worked. You should have recoding dine first but Bmw will try a full istep update (they don’t do single modules) which is the entire car my advise is get a coder to do it for you kubax86 cost only 90usd for his time. It’s very quick and prob cheaper than the hidden cost of KW to drive to dealer and not having you car for a few days/insurance swap etc. Also safer as it’s only 1 module and BMW won’t be able to tell as he replaces it with the same level software just a clean version. Kind of like reformatting your computer/phone and reinstalling the GUI. Regards the ACSM even when I got my VDP changed and voltages working the car was over reactive on small bumps but only in the rear so I suspected the ACSM as it sends all signals from sensors across the fibre optic system. Kubax blanked it and recoded and presto everything finally works. BMW don’t have a clue about this system they will tell you it’s buckled alloys, tyres , all in your head, normal etc etc but if you have had your alloys checked and they are good and BMW don’t see damages shocks or bushings and your VDP voltages are good then it’s likely the ACSM. BMW techs don’t even realise it’s what controls the flex network they think it only controls the airbags. |
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01-08-2023, 03:21 PM | #20 |
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Thanks for the reply CnSky!
My car is only 6 months old so it is still under warranty so I will return to my dealer with my VDP findings and at least can do so confidently since you confirmed that my readings are correct. I will also mention the potential ACSM issue as well although I don't expect that they know too much about this stuff since last time they concluded that the issue was related to tyre pressure (which it obviously wasnt).. Anyways I will contact my dealer and will certainly update you on the outcome of this. Thanks again! |
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01-08-2023, 03:23 PM | #21 |
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Ask them to check voltage on a similar car and then yours when at standstill. The issue can’t then be ignored as it’s clear there is a problem. Best of luck - BMW aren’t able to fix their own cars these days and don’t understand them. Let us all know how it goes.
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01-08-2023, 08:45 PM | #22 |
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Hello CnSky,fogive my poor english,my 520i had the same problem,this is my standstill current(im left drive not right drive):
rear left:0.00mA rear right:0.00mA front left:4.00mA front right:1.00mA And I god the message that in the standard equipment configuration(s223a edc from g30 or g12), information about the vertical body movements (pitch, roll and lift) is made available by the Crash Safety Module ACSM-High. The retraction and extension speeds of the shock absorbers are determined by means of the ride height sensors. If the vehicle is equipped with the optional equipment “Active Comfort Drive” (2VS or 2VA), there are additional wheel acceleration sensors. These are used among other things for more precise regulation of the Electronic Damper Control (EDC). Obviously, the vdp dynamic signal of our low configuration car is only from the ACSM,the height sensor only determines the speed of the shock absorber piston. This also explains why I can effectively restrain the rebound speed of the rear shock absorber after subtracting 25 mm of the rear axle height from the height adjustment at ISTA+, because the height sensor only affects the damping speed. Experts told me that the lack of vertical acceleration sensors is the cause. The vertical acceleration in ACSM is not independent of four axes, so the accuracy is very poor. However, it is strange that Mercedes, which also uses the same bilstein damptronic sky absorber, does not need vertical acceleration sensors. It can achieve stability close to the magic carpet by using only four height sensors and four lateral acceleration sensors outside. So now I don't know how to do it or whether to install 4 vertical acceleration sensors. Last edited by cn520; 01-08-2023 at 08:52 PM.. |
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