Draining battery

[Exerqtor]

And the fight goes on

Did a MMI/Navi update yesterday (had P0022 on the mmi ), and that ofc. didn't go as planned either. First from P0022 to K0031 the "DVD device" update didn't go thru (took retry several times), and at last i had to skip that module. Then went to update from K0031 to K0257 the "MU9307 Device" pooped out. I sat down trying to retry that for well an hour since i don't know what the MU9307 actually is and was afraid it was a needed/high priority system. When i canceled that and all wrapped up i ended up with "MUConsistency -NOK" in the software update device summary.

I later found out that the iginition is supposed to be OFF, which i didn't know when i did the actuall update, i had a 50a supply charger on that i usually use when i update/troubleshoot cars though so the battery voltage never went bellow 12,3v. But apparently that's to low and might be why the updates failed(??)

After that i did a test start and quick function check of the car, and all seemed fine so i went forward with the Navi update and that went without a hitch. So did the MMI/Navi activation after that was done.

So when all that was done i drove the car home for the night (10.30pm at this point), and i tested the navi on my way home, and it worked ish. Route calculated and all that, gasstations and all those icons came up, but i couldn't see the road itself on the MMI, the voice guidance and dash guidance worked though.

So i drove it home and parked the car, without a charger to see what happened. And yeah, it was flat today as well -.-"

But ok, with all that said and done! Is it possible / how do it get to update the two devices that craped out on me? Feel like i have to sort that c**p out before i go any farther with the draining problem

[Delboy]

This is going to be a pain to sort out.

The usual culprits are dodgy door handles

Faulty alarm module

Some part of the mmi keeping the systems awake which i would be inclined to try first as you said the handles all work as they are meant too.

If you buy from eBay a most fibre bypass loop you can isolate parts of the most loop with it and unplug that module to narrow down which device is doing it.

Or if you are handy with a multi meter you can measure the voltage drop over fuses to find the culprit.

[Mechcanico Lee]

Why is battery monitoring/energy monitor ecm not shutting down all ignition circuits when quiescent voltage drops below threshold to ‘save ‘the battery ?

Can you use a shunt inline with battery lead and measure the drain whilst car is asleep , roll boot latch over and wedge the spring loaded press in type switch on boot lid .

After say 20 mins see how many amps it’s pulling out , see if amps is a steady draw or doing any cycling or surging .

My a8 used to have dickie door handles and would wake up through the night when it was raining, but energy monitor would always clip it and I never had a flat battery on it .

I’m wondering if the body module not going to sleep ( gear stick back lighting staying lit ) is a consequence of another draw on a circuit that is not isolated by the energy monitor ecm .

[snapdragon]

My car has often been like this after using VCDS. I used to run a scan for 5-10 mins, shut down, lock up and in the morning a flat battery and battery - 10% on display. It seems better if you make sure you close controllers and unplug the interface from the ODBII port before you turn off the ignition.

[Big Dave]

10% on the display? Have a read of this, it may be relevant:

[Exerqtor]

Originally Posted by Delboy

This is going to be a pain to sort out.

The usual culprits are dodgy door handles

Faulty alarm module

Some part of the mmi keeping the systems awake which i would be inclined to try first as you said the handles all work as they are meant too.

If you buy from eBay a most fibre bypass loop you can isolate parts of the most loop with it and unplug that module to narrow down which device is doing it.

Or if you are handy with a multi meter you can measure the voltage drop over fuses to find the culprit.

Yeah i know these kind of things suck to solve, so i hoped this might be a know issue and save alot of time

Since the drain is a s big as it is i hope to be able to meassure it pretty "easy" with the multimeter. I mean it has to be quite a big drain to fully empty a 105Ah AGM battery in under 10 hours :/

Originally Posted by Mechcanico Lee

Why is battery monitoring/energy monitor ecm not shutting down all ignition circuits when quiescent voltage drops below threshold to ‘save ‘the battery ?

Can you use a shunt inline with battery lead and measure the drain whilst car is asleep , roll boot latch over and wedge the spring loaded press in type switch on boot lid .

After say 20 mins see how many amps it’s pulling out , see if amps is a steady draw or doing any cycling or surging .

My a8 used to have dickie door handles and would wake up through the night when it was raining, but energy monitor would always clip it and I never had a flat battery on it .

I’m wondering if the body module not going to sleep ( gear stick back lighting staying lit ) is a consequence of another draw on a circuit that is not isolated by the energy monitor ecm .

I think that's strange to, maybe because the drain is so big that it kinda "skip it"?

I've always clicked the boot latch when working on the car and let the trunk stay open, but what does that little press switch do btw?

The shift indicator not going black along with the headliner buttons and such's is so damn strange imo, at least without any faultcodes assosiated with it!

I have to sort out the MMI updates and make sure all that works first now anyways.

Originally Posted by snapdragon

My car has often been like this after using VCDS. I used to run a scan for 5-10 mins, shut down, lock up and in the morning a flat battery and battery - 10% on display. It seems better if you make sure you close controllers and unplug the interface from the ODBII port before you turn off the ignition.

Ok? Never heard of that issue before, but i usually close all controllers and VCDS plus switch the ignition off before removing the OBD plug.

[Delboy]

The reason the battery goes completely flat is the bem is only capable of shutting down non critical loads, if you study the electrical diagrams you'll see that most devices are wired in a way where they connect directly to the fuse box and if that device doesn't go to sleep or is not controlled by the bem then it's going to continue drawing current.

The lights on the console are a sign that the cars not going to sleep and is constantly sucking the life out of the battery.

I have had door handles do it too me, i've seen on the internet things like bad instrument cluster, tv tuner, water in mmi panel, faulty alarm and probably more that can cause this so its just a matter of figuring out whats pulling it down.

Have a look at the attachments, give you a place to start.

[Exerqtor]

Originally Posted by Delboy

The reason the battery goes completely flat is the bem is only capable of shutting down non critical loads, if you study the electrical diagrams you'll see that most devices are wired in a way where they connect directly to the fuse box and if that device doesn't go to sleep or is not controlled by the bem then it's going to continue drawing current.

The lights on the console are a sign that the cars not going to sleep and is constantly sucking the life out of the battery.

I have had door handles do it too me, i've seen on the internet things like bad instrument cluster, tv tuner, water in mmi panel, faulty alarm and probably more that can cause this so its just a matter of figuring out whats pulling it down.

Have a look at the attachments, give you a place to start.

Hmm ok sounds logical, but when you say you've had door handles do that to you. What did you end up doing there? Disasemble the door handle and swap out the switches and coat it up with some conformal coating afterwords? Or swaping out the entire handle? Never had the door panels, let alone the handles of a D3 before so i have no idea how there made lol.

Thx for the doc's mate! I hope i get some time this weekend to reflash the MMI and hopefully get that working so that i can go on with the messuring the drain =/

[Delboy]

I just replaced the whole door handle, as I didn't want to go down the route of having the car apart for ages while trying to pull apart the handles.

They are potted and built in a way to stop you from doing that, it's not impossible but time consuming.

Actually in the years that I have owned the car I've had to replace all four.

[Exerqtor]

Hmm ok sounds reasonable

How did you check yours? Manually check for continuity on the connector pins when pushing the buttons?