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D3 - Axles, Brakes, Suspension and Steering Brakes, Springs, shocks, steering racks, steering columns, suspension arms, wheel hubs etc.

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Old 1st March 2024, 05:37 PM
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zed_thirteen zed_thirteen is offline
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Default I keep losing air suspension lift option on acceleration

Strange fault. If I accelerate the light function is disabled and comes back on under heavier than normal braking

Any ides what could be causing this? I was wondering about the level sensors or maybe the pressure sensor on the pump wiring?

It's fine if I drive sedately and the functions do work when they haven't been disabled

2003 A8 D3 3.7l petrol quattro
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Old 2nd March 2024, 09:54 AM
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Quote:
Originally Posted by zed_thirteen View Post
If I accelerate the light function is disabled...

It's fine if I drive sedately and the functions do work when they haven't been disabled
To begin with, I'm going to assume that the word 'light' should be 'lift', and you're referring to the Lift mode on the MMI screen, and not the yellow and green warning 'lights' in the instrument cluster. Can you also clarify 'sedately' in terms of speed?

With that in mind, I wonder if you're just experiencing exactly what the air suspension is designed to do. The following snippet mentions the limitations of the Lift function, so if 'sedately' is under 63mph, then this would appear to be what's happening.

Further detailed information about the air suspension can be found in the following PDF from the 'D3 Tech dump' section:

56-SSP 292 adaptive air suspension in the Audi A8.pdf
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2001 A8 D2 FL 3.7 Q - LPG Conversion, Engine: AKC, Gearbox:FBB, Colour:LY5X Aqua Blue pearl effect, Interior:WJ light beige/dark beige valcona leather with burr walnut inserts

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Old 2nd March 2024, 10:54 AM
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zed_thirteen zed_thirteen is offline
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yes, I did mean lift.

I cant really describe the rate of acceleration. .If I accelerate quite quickly (not maximum warp!) then the lift option on the MMI becomes disabled. It tends to stay like this until I brake quite sharply (gentle braking doesn't seem to enable it) I think it might cruise for hours in the disabled state until fairly sharp braking occurs again?

I will check out the link you provided though - thank you
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Old 2nd March 2024, 12:11 PM
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Quote:
Originally Posted by zed_thirteen View Post
If I accelerate quite quickly (not maximum warp!)
Would that be like doing a 0-60 run type acceleration? You mentioned the level sensors, and that might be the issue, although I would have thought that if there was issues with one of them regarding readings, it might flag up one of the suspension lights.

I can't think how mechanically a level sensor can get 'stuck', if it still attached properly, so maybe a dodgy connection due to water ingress, or water ingress into the actual electronics.

Do you have VCDS or other diagnostics tool that you could use? I suspect there's bound to be measuring blocks in module 34 (Level Control) that you could check for the four sensors, to see if they are all within the same tolerance. In theory, you should also be able to check these values whilst cycling through the various suspension settings. Then again, they might all show up as fine whilst stationary. VCDS does allow you to log data, so maybe you could start logging the four sensors, go for a normal drive, and try to replicate the issue, and then check the results.
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2001 A8 D2 FL 3.7 Q - LPG Conversion, Engine: AKC, Gearbox:FBB, Colour:LY5X Aqua Blue pearl effect, Interior:WJ light beige/dark beige valcona leather with burr walnut inserts

My DIY jobs - Replaced alarm horn, Replaced Coolant Temp sensor, Updated RNS-D firmware, Installed Reversing Camera and Digital TV, Dashcam Installation, Retrofitted Rear Blinds, Auto-Dimming Rear View Mirror, Chrome Boot Struts

Sold! 2008 S8 D3 5.2 V10 - Engine: BSM, Gearbox:KLW, Colour:LY7F Suzuka Grey Pearl Effect, Interior:Black/Black with Silver/Black valcona leather with carbon atlas inserts, Bang & Olufsen, Heated windscreen, Soft-close doors, TV, DAB, AMI, Quad Zone, Auto Boot, Auto dim Mirrors, Keyless entry, PDC with rearview camera, AFS II Headlights

My DIY jobs - Fan Jet Windscreen Washers, Retrofitted Electric Side Blinds
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