Air Suspension: System Fault

[MTV10]

For the past week, I've been getting an air suspension fault. Happens randomly when driving. Suspension becomes very stiff, can't put ESC into Sport, no adjustability available....

Restarting the car clears the issue.

What gives?

[D3adish]

A-Premium Headlight Level Sensor... https://www.amazon.com/dp/B07PMLMBCW...p_mob_ap_share

Possibly one of these sensors. Had the same error in my 2014 S7. Issue resolved after replacing my front passenger one. Super easy replacement.

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[MooreS4]

It could be a leak or a level sensor issue amongst other things. I suggest getting it checked quickly. I recently had the same issue and the light would go off and periodically return without a change in ride height. It turned out to be a leaking front air strut which burnt out my air compressor.


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[MrCUK]

Have the car scanned for codes - that is the only way to narrow down the issue, that should be the first thing you do :)

Once you have the codes then we help further,

Thanks

Sean

[MTV10]

I scanned it with my JB4 app and nothing came up. I'll bring it to the shop next time this malfunction occurs and have them scan it with VCDS.

[MTV10]

Some developments today. . . .

[widebodyfx]

Is this happening at speed only? Cete module is set to defeat or allow the speed lowering?

[MTV10]

Yes set to 250kmh

[widebodyfx]

Got it I used to set it crazy high too so it wouldn't be an issue. Have you tried using the dummy plug and see if it stops happening?

[rabbitarmy]

does the car need to be "asleep" to prevent canbus errors when installing the bypass dummy plug?

[widebodyfx]

Not as detrimental as during the module install which takes everything on that bus offline. Would probably still wait til the system powers down.

I’ve had these types of at speed alerts on my old S6 but that was with VCDS and H&R module lowering which ended up being fairly low but no defeat on the speed lowering with that combo.

One way to know you’re kinda on the edge of the range is the headlight leveling sequence at start up no longer happens. Can be switched to another option to regain the leveling sequence but it’s still way lower than it wants to be for the various systems to operate as designed.

[MTV10]

Haven't had any issues in the 2.5 years I've had this car. Have run it slammed the whole time. Now this is happening. Something is up.

I will put the CETE dummy plug in and see if this continues.

[SteveO34]

Agree with the others that you don't want to let this go. I've had a bunch of problems with the air suspension and once something goes wrong, it will only get worse. In my experience the red warning light means there is a significant leak and/or your compressor is shot. But you need to get the fault codes so we can determine better. You shouldn't have to wait until the fault comes back to get the codes read. Chances are the DTCs (fault codes) are logged and still active, even if the warning messages don't always come up on the dashboard.

[aaronsananikone]

Get under the car/take off your tires and check all the level sensors, you may have snapped or bent an arm or maybe the sensor plugs got damaged somehow... something similar happened to me, snapped the ball off an arm when I was adjusting my fitment and I would get random codes and the side that had the snapped arm behaved all crazy... IDK, worth a shot to just check

[Audisthesia]

Out of curiosity, go into your car settings in MMI, see if tire change mode is checked.

[MTV10]

Out of curiosity, go into your car settings in MMI, see if tire change mode is checked.

I had checked that when it first happened.

[Audisthesia]

Did you ever get in touch with someone with VCDS to scan it?

[MTV10]

Did you ever get in touch with someone with VCDS to scan it?

No sir. Been busy over the holidays.

I opened up the side compartment in the trunk. Unplugged the CETE module, re-plugged and re-tucked everything back in, just in case there was a wire pinched or something of that nature. Been a couple days now and no codes...

[widebodyfx]

That’s unsatisfying that it somewhat went away. Maybe tire pressures down from cold spell or something? You’re definitely one of the slammered cars here.

[MTV10]

That’s unsatisfying that it somewhat went away. Maybe tire pressures down from cold spell or something? You’re definitely one of the slammered cars here.

That will typically always trigger TPMS on the dash, not Air Suspension Fault.

Anyways .... been a couple days now and zero issues. Weird....

[Yeoman]

I've run into the exact issue.. Typically re-adapting the air suspension will clear those recurring faults, especially if you lowered it significantly. The process to reset can be found on the VCDS forums - it worked for me

https://forums.ross-tech.com/index.php?threads/12737/

[MTV10]

Strange, though, that I've had this thing slammed for over 2 years now and this starts happening out of nowhere. . .

[widebodyfx]

Is virtual TPMS very sensitive to pressure changes? I think I've dropped 5psi from switching wheels and it does not alert me, noticed the same with a Volvo. Dropped a fair bit 7-8psi before it alerted on the dash.

[MTV10]

Is virtual TPMS very sensitive to pressure changes? I think I've dropped 5psi from switching wheels and it does not alert me, noticed the same with a Volvo. Dropped a fair bit 7-8psi before it alerted on the dash.

I've noticed about the same.

[Audisthesia]

Is virtual TPMS very sensitive to pressure changes? I think I've dropped 5psi from switching wheels and it does not alert me, noticed the same with a Volvo. Dropped a fair bit 7-8psi before it alerted on the dash.

What is this "virtual tpms" you speak of? I'm not familiar. Another term for indirect?

A/S cars have indirect TPMS (uses abs wheel speed measurements and not special valve stems, also no per tire pressure readings); RS cars use direct TPMS which does have special valve stems and provides per tire pressure reading.

[widebodyfx]

Yep the indirect, yes I know about the RS and peasant versions. HAhahahah, I kid,

[Audisthesia]

Yep the indirect, yes I know about the RS and peasant versions. HAhahahah, I kid,

every c7 is a peasant next to your rs7

[widebodyfx]

I'm a peasant next to the RS7....

[Audisthesia]

I'm a peasant next to the RS7....

I mean, the name explains things... Wide+body

[Yeoman]

Strange, though, that I've had this thing slammed for over 2 years now and this starts happening out of nowhere. . .

It's not so much the overall lowering amount but that one corner can be significantly out of lower (or higher) than the rest, causing an issue. Getting everything measured and re-adapted assuming stock values, then lowering back may help.

[MTV10]

Cae has been issue free for a week. Started acting up again last night. Dummy plug did nothing... so that rules out the CETE module.

Unplugged the battery overnight to give it a nice reset. We will see if that solves it.

[widebodyfx]

With no Cete in there that should rule out the too low variable. Have you looked at the codes?

[MTV10]

Haven't had a chance to visit the garage.

However, after unplugging battery overnight car has been trouble free. Let's hope this issue is resolved.

[MTV10]

Issue has come back this week....

Just got the car scanned. My mechanic has no idea what could be causing the issue since it gives all 4 sensors as faulty.

Any ideas?

[MTV10]

Left shop and fault came right back...

Doesn't narrow anything down.

[widebodyfx]

You have all 4 corners reporting an error plus 1 mechanical error. I don't see a follow up from the OP in this thread but he had some of the same issues. https://www.audizine.com/forum/showt...lt-c1048-c1031

[MTV10]

Only the Fault 455693 came back. Based on this thread below... seems to be front right sensor.

https://www.audiworld.com/forums/s7-...codes-3019272/

[widebodyfx]

Gotcha, was looking at the first set of errors. Hopefully, just 1 sensor is on the outs. Rear sensors sound like they are more of a PITA compared to the front.

[Yeoman]

Did you try to re-adapt the air suspension at all 4 wheels and then lower it back? As I mentioned, I had the same issue and this fixed it for me.

https://forums.ross-tech.com/index.php?threads/12737/

[MTV10]

Just replaced front right sensor. Code still present.....

Guess I will try and re-adapt air suspension. If that doesn't work.... off to Audi she goes.