Electrical System Problem
I took delivery of my beautiful A8L on New Year's eve. Thinking to show off my amazing new ride to my nephews on New Years' Day, I jump in with the boys and... dead battery.
Well 21 days later and I've only been able to drive the car to and from the dealer as they attempt to fix the problem. I mean that literally - no other trips except to/from the dealer.
The latest theory is that the intelligent power management unit is faulty. No spares in the US of course, so an order is placed with Germany. And they're not really sure that the power management unit is actually the problem.
I may have to pull the plug on this vehicle. My dream car has turned into a nightmare wagon. The notice arrived in the mail for the second monthly payment, and I've not been able to use the car at all.
I've told them that I've lost confidence in this car, and want a another vehicle unless they have it fixed in two days. I pulled my AoA rep into the story and gave him the same message. The dealer has been "OK" during this disaster. Not perfect, but not horrendous either.
Someone wrote on another thread that the A8 is so new the techies really don't know much about them. I've found that to be true *in spades*. The service manager was not even aware that the MMI includes a battery level monitor.
I love the car that I've come to call The Big Easy, but maybe I should opt for a pocket rocket like an S4. And save $25k in the process.
Thoughts anyone?
I'm so sad :-(
Mike
Regardless, if it's an electrical problem, should be able to be troubleshot and repaired. That's the beauty of electrical systems, when they are broke, they can be fixed to like new standards relatively easy.
But in your case, I would think you would want to get two payments from Audi (or until they properly fix it) for your hardship.
Or if you don't want to put up with it, tell them to give you another one in exchange or buy back.
I feel sad too! That stinks!
pw
what it means is that if you leave something on, the computer will start shutting down things one by one to save energy for cranking if the voltage drops too low it will disable all consumers off
about thech is true most don,t know much about this systems because is new to audi but is been used for a few years now on mercedes
they should be easy to check where the draw is after all still is a 14 volts electrical system very basic but they expect the computer to find the problem for them
it uses the can bus to regulate loads and, if necessary, deactivate functions causing loads. its aim to ensure that the vehicle can always be started.
specifically the control unit monitors the battery charge and the starting capability.
it sits in the boot above the battery, and triggers the battery cut-out relay. there are 3 functions:
1) battery manager - always active
2) closed circuit manager - deactivates loads as required when the engine is not running
3) dynamic management - regulate charging voltage regulation and load reduction with the engine running.
as inputs, it takes many via the can (both hi and low), but specifically monitors battery temperature, voltage current and operating times.
the mmi will display the battery charge, and should alert the user before it starts shutting down loads with the engine off (asks the punter to start the engine).
there are 6 progressive deactivation stages, which can be monitored via vag-com. (stage 4 is special transportation stage for the voyage out from the factory). stage 6 is the bare minimum required to start the car. stage 2 is activated if the battery draw is >50ma after 3 hours.
use of any of these stages will trigger a fault entry. similarly the measuring blocks give access to all necessary parameters (battery condition, temp etc).
battery diagnosis can be determined by vag-com. however a new battery should not be connected unless adaption is undertaken (menu item "battery manager encoding").
hth
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I agree completely that electrical systems are repairable, but I was not about to have them work their learning curve on my dime.
Belive me when I say that I am very good at standing up for myself.
I'll provide an update to the story in another post.
Thanks for your comments, though.
Mike








