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Discussion Starter #1
Hello all,

I've got a 2008 EOS 4 cylinder turbo that I've been having a parasitic drain issue with.

I checked the drain across the fuses with a full battery and the car completely shut off and found two spots. One was the radio fuse drawing about 330 mA and the other one was drawing about 450 mA and I'm not sure what it specifically goes to but was labelled as F23/SB23 (See attached diagram).



I took it out and the car would turn over, but not crank. I put it back in and it cranked just fine. I think it connects to the ignition and that I may have an ignition relay that's left open, but I'm not sure.

Does anyone know where the ignition would be based on the diagram?

Or even better, has anyone had this issue and know how to fix it?
 

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Hello all,



I've got a 2008 EOS 4 cylinder turbo that I've been having a parasitic drain issue with.



I checked the drain across the fuses with a full battery and the car completely shut off and found two spots. One was the radio fuse drawing about 330 mA and the other one was drawing about 450 mA and I'm not sure what it specifically goes to but was labelled as F23/SB23 (See attached diagram).







I took it out and the car would turn over, but not crank. I put it back in and it cranked just fine. I think it connects to the ignition and that I may have an ignition relay that's left open, but I'm not sure.



Does anyone know where the ignition would be based on the diagram?



Or even better, has anyone had this issue and know how to fix it?


Just a thought but could it be the canbus as some early models fitted with the RNS 510 head unit would suffer a battery drain.

Mick


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Just a thought but could it be the canbus as some early models fitted with the RNS 510 head unit would suffer a battery drain.
Mick
That was actually good advice because power consumers on the CANbus should go to sleep and if it isn't the radio it could be something else.

There's no point pulling a fuse with ignition off and thinking you are measuring parasitic drain, because the Canbus can take up to 3 minutes to put controllers into sleep mode and go to sleep itself. :(

You should start at the battery terminal whilst waiting and watching for the time point when current drops which is initiated by the CANbus sleep command. Then keep watching for up to 5 minutes and any drain you are left with over about 50mA will be parasitic drain you have to find. I've already explained how to do this in a previous post. If you or somebody else has been swapping electronic controller modules for so called later versions of Chinese clones, some system compatibility issues have been found to cause this problem. :confused:
 

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Discussion Starter #5
Thanks for the help! I turned everything off, latched the doors, and all that jazz and waited about 20 minutes for everything to shut down. Sure enough, I did not measure any drain across the F23 fuse, so the computer is shutting down that.

However, the radio is still drawing about 415 mA even after waiting. It's not a gps system, just what I'm guessing is the standard radio in it (shown below).



I'm not sure if it's the stock radio or not though.

So now that I've been able to identify the issue, or what appears to be the issue at least, my next question is what to do about it. My temporary solution is to simply remove the fuse, but of course I want something more permanent.

Is this something that could be re-programmed with a VCDS, or do I just need to invest in a new radio?
 

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OE Radios in V.Ws have CanBus communication so the car can tell it to switch on or go to sleep. Some early substitutes didn't have this and folks had to try hooking up power direct to ignition switches. But this doesn't work with V.W because the ignition switch justs sends low level voltages to the controller. If you used diagnostics to scan your car you would know if it was on the CanBus because it would be found as Radio 56 and diagnostics would show the V.W part header it read over Canbus. There are no options in vcds to program anything although there is a very good test routine to check all the speakers. This would only work on a VW stock unit if vcds is able to talk to it over Can.

Can you turn off the radio with the volume push on/off switch and is there then no current drain? The radio unit is fairly easy to remove and you may find labels on the back, but a diagnostics scan is easiest. The VW radio connector on the back has two wires (orange?) which are the CanBus system connection. But if your radio turns on with the ignition switch I would think it has some kind of canbus control.

It looks like a stock radio, but you need to confirm it. GPS has nothing to do with parasitic current drain. 415mA is a lot and I'd expect the display to be lit for that! A CANbus controller module should only be tens of mA before it auto sleeps so it sounds like your radio amps are still powered?

I share your concern with this problem because if you park your car, your battery will be flat in less than a week!
 

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Discussion Starter #7 (Edited)
So it sounds like a legitimate replacement might be the best option. That being said, can the 2008 model be upgraded to the rns 510 unit?
 

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So it sounds like a legitimate replacement might be the best option. That being said, can the 2008 model be upgraded to the rns 510 unit?


Yes the the RNS 510 can be fitted but you will have to upgrade the canbus to a later one as the early ones caused a battery drain.

Mick


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you will have to upgrade the canbus to a later one as the early ones caused a battery drain.
Be careful if you buy the later canbus control module. I bought a cheap Chinese one and got a battery drain problem I never had. :( The cheap Chinese clones are often 'emulators' using their own software and in my case I think they stole and copied an old (bad) copy of the V.W firmware from an older version.

If you buy a new or used genuine V.W part - look carefully at every letter in the part no. versus an online part catalogue. If you don't see that exact same part number (no lettters different) it could be a poor clone.
 
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