Technical battery drain issue.. Please help!

[07misanored]

Hi guys, just picked up my new to me 2007 misano red RS4 last week and first off I must say what an incredible car. It is everything I was wanting and more. I looked the car over top to bottom when purchasing it and it is in great condition. Everything works flawlessly, great service record, and I was convinced it was in perfect health....until I left it parked without driving it for about 10 hrs and came out to a dead battery.

Being an engineer I measured voltage acrossed the bat with a meter and it was 8 volts....realllllly dead...and noticed the bat was recently replaced about 2 months ago indicated by the Sticker on the side of the battery. I found this strange as I didnt remember leaving anything on or open. So I put the bat on my digital charger which said the battery was still servicable and brought it back up to full charge slowly over many hours and placed it back in the car. I then went for a drive and everything was great and working properly. Voltage with car running was ~14 volts so alternator is doing its job. Got back home and parked the car, turned it off, unbuckled, opened the door, closed the door, locked the doors, and sat in the car for a few moments to see if I could find anything obvious staying on draining the bat. Well...good thing its quiet in my garage cause very faintly I could hear the fan in the back of the navigation unit on. I know there is a shut down period for things like that and thought maybe if I sat in there it would turn off after a period of time....well i sat in there for 1 whole hour and it was still on.

So my next step was to measure exactly what was going on in terms of current drain on the battery. So i hooked up my Fluke multimeter to the battery and positive lead to measure current. Took the key out of the ignition, opened the door, closed the door, locked the doors, and waited a bit for the car to go to sleep. The lowest the current draw got to after about 20 mins was 3 amps! or 3000mA. No wonder I had a dead battery! So next I pulled the 20 amp fuse titled "radio" from the panel and repeated the same test. Current draw was all the way down to .3 amps or 300mA. This was a lot better but still higher than what I knew it should be. So then I also pulled the 10 amp fuse titled "Instrument Cluster and Navigation" and performed the same test again. The current drain then read a mere .04 amps or 40mA which is a very acceptable reading and would last weeks at that level before the battery was dead.

So ive identified the problem....something is keeping my navigation unit and stereo amps from turning completely off! I need suggestions on where to go from here guys. So far I have two ideas but would love you guys to chime in and let me know what you think.


1. My nav (rsn-e) is on firmware version 0150 which is a somewhat older version, and I have read places that there is a bug with some combinations of ecu and nav software versions that keeps them from communicating properly and the nav from properly shutting down completely.


2. Whenever the instrument cluster is on in the car there is a faint "buzzing" that comes from behind the cluster area. I know there are several relays mounted behind there and I am wondering if one is bad, as bad relays commonly buzz, and it is not fully dis-engaging when it should be, letting just enough juice through to the nav to keep it awake even though it shouldnt be.

Sorry my first post is so long and technical but I am anxious to get this little issue taken care of so I can get back to enjoying this incredible car. Thank you in advance for any suggestions, help, information, or ideas. Look forward to enjoying this forum.

[adsgreen]

Software 0150 is crazy low iirc the latest iirc is 0650.

Of you can find any Audi owner with a later DVD then this should update automatically. Maps should still work but no guarantee however my car came with 2006 DVD and I used a 2011 to update and it still works fine.

Considering its a 15 minute job definitely worth doing and see what happens.

Thing I don't get is that it is such a massive crippling problem that I would have thought in 4-5 years it would have been resolved by a previous owner so must be recent... Perhaps the rnse is a new addition?

[07misanored]

exactly what I was thinking regarding the software....perhaps the engine ecu was updated to sw0080 or sw0090 and that doesnt play nice with the ancient nav software. The funny thing is I do think that the problem has been there with the car for a while because I found a piece of paper in the battery area for a
PriorityStart! Automatic Battery Protection Disconnect from BLI International...which upon research is basically a switch that automatically disconnects the bat when it hits 11.7 volts to prevent further discharging. So while the device was/is no longer on the battery now...I am assuming it was used in the past as a way to "live with" this issue instead of actually resolving it. Talk about a band-aid fix! As far as I know the rnse was a factory installed option.

[ArthurPE]

I have no input on what the solution is, but that is a heck of a problem statement and troubleshooting/results report!
I need to hire people like you, lol

as you said, 3 A is crazy high, 72 AmpHr per day, a large percetage of the battery capacity the 0.3 is much better ~ 7.2 AmpHr, but still will kill it in a few days if not run

are there any aftermarket mods? stereo, alarm, tracker, etc.?

[ArthurPE]

quick thought: did you pull the cluster fuse (with the nav fuse in) to see if the nav shutdown?
initial 3 A both fuses in
pull cluster fuse (leaving nav fuse in)
measure 0.3

[07misanored]

Yeah as I said I am an engineer and am very methodical in my troubleshooting haha.. No aftermarket alarm, tracker, or stereo installed. ArthurPE I did try pulling just the "cluster/nav" fuse while leaving the "radio" fuse in...that situation also gave me the proper 40mA reading. I think I've figured that the fuse titled "radio" is the power for the bose amplifiers, hence its large 20 amp size...and the "nav/cluster" fuse is the power for theinstrument cluster and the rnse. So pulling the "nav/cluster" fuse shuts the rnse completely down and since I also believe the rsne signals the bose amps when to be on... no power to the rsne = no signal to bose amps to be on = no power draw from them through the "radio" fuse. I am brainstorming on where to get ahold of a newer nav dvd without spending 200 on it to update my firmware and see if that changes anything.

[Timster]

Where abouts are you? There's plenty of folk on here that will gladly help out with the loan of the disk.

The RSNE has a very.... very long shut-down (IIRC, 30 mins).
I'm sure PetrolDave will be along shortly to provide the facts and figures.

[m5killer]

strange... i have aftermarket set up including two big alpine amps but with original audi head unit....and the electrics do take about 30 odd mins to shut down....my battery has never been changed and the car has sat for 5 months in summer and then started without a jump.....and 3 months in a very cold winter and just started without a jump....so for something to kill that big battery is not easy...think you would need more of a drain than that to kill it in a few weeks.....

[adsgreen]

Even a dodgy cd copy from eBay would upgrade the nav ok. I wouldn't use the copy DVD permenately as there are reports of the laser working too hard and burning out.

Any audi model would do.

I thought the rs4 had a battery protection system built in like most cars. It's why the cigarette sockets are perm live- even if you left something in if the battery dropped too low it would disconnect it

[m5killer]

as above it has got a protection system...and also goes to sleep after a while hence why i could start my car first go after sitting for 5 months

[07misanored]

I dont know much about the battery protection system...and whatever my problem is is obviously causing mine not to work. I am in the process of downloading and making my own rns-e update cd. I am going to update it to sw0200 and see if perhaps that changes anything and allows the nav unit to fully shut down after ~30 mins. If I do get the software to update correctly and the nav unit still stays on after I sit in there for another hour I think I will turn my attention to the faint "buzzing" coming from behind the cluster and identify/replace what is making the noise and replace it.

[adsgreen]

The buzzing could be the rns-e fan.

0200 is still very old - mine came with 0550 and works fine with 0650.

[PetrolDave]

The buzzing could be the rns-e fan.

0200 is still very old - mine came with 0550 and works fine with 0650.

I think 07mizanored may be in the US - where the SW versions are completely different. The latest US SW version is 0260 - but that disables all AV inputs, so many people run a modified version of 0200 that pretends to be 0270.

[PetrolDave]

So ive identified the problem....something is keeping my navigation unit and stereo amps from turning completely off! I need suggestions on where to go from here guys. So far I have two ideas but would love you guys to chime in and let me know what you think.


1. My nav (rsn-e) is on firmware version 0150 which is a somewhat older version, and I have read places that there is a bug with some combinations of ecu and nav software versions that keeps them from communicating properly and the nav from properly shutting down completely.


2. Whenever the instrument cluster is on in the car there is a faint "buzzing" that comes from behind the cluster area. I know there are several relays mounted behind there and I am wondering if one is bad, as bad relays commonly buzz, and it is not fully dis-engaging when it should be, letting just enough juice through to the nav to keep it awake even though it shouldnt be.

What are the conditions when you measured the current drain? You may have made a faulty diagnosis...

The RNS-E only turns off AFTER you lock the car, and NOT when you turn the ignition off. Repeat the measurements with the car locked, if the current drain is still there then the first thing to check is if the RNS-E has any CAN bus fault codes (it's a CAN bus message that tells the RNS-E to turn off).

The RNS-E turns on when you UNLOCK the car, and stays on until either 30 minutes after you turn the igniton off or you LOCK the car (whichever happens first). This is so that it's booting before you start the car and doesn't need to reboot if you only stop briefly.

The buzzing you are hearing could well be the RNS-E cooling fan or the DVD drive.

[merlinus98]

...
then the first thing to check is if the RNS-E has any CAN bus fault codes (it's a CAN bus message that tells the RNS-E to turn off).
The RNS-E turns on when you UNLOCK the car, and stays on until either 30 minutes after you turn the igniton off or you LOCK the car (whichever happens first)...

I had this kind of problem, due to a faulty iPod or bluetoth adapter that sometime cut the CAN bus: my RNS-E didn't turn on/off automatically, if I turned on manually, it stopped itself after 30mn, stay on even 5mn after I stop and lock the car (and anything else stopped) !
And my battery had a big drain...

iPod adapter unmounted, bluetooth rewired, original battery (5 years old) changed: all is ok