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Discussion Starter #1
A very odd problem. During the day before 2pm the clock on my RNS-E (EU) unit is reasonably accurate (within 15 mins of the clock in the cluster). At this point the arrival time as also fairly accurate.

After about 2pm the clock in the RNS-E is wildly off (6 hours or more) and of course arrival time is similarly useless.

Has any come across this problem before, and how do you fix it?

Background:
Car - 2001 Allroad
Time settings: RNS-E is set to sync with the clock in the cluster (the only available option).
 

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That's the known time/date issue where the RNS-E changes to synch its time with the cluster when it sees a CAN, but the cluster in the older A6 C5 and A4 B5 doesn't support the time signal. If you browse this forum you will find several references to this issue but no final solution.
 

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Pardon my lack of detailed knowledge of how CAN works, but it's a network, right? Is there any way another device could be put on the network that provides time? Even if the built-in time on the cluster wouldn't sync to it, you could get the times fairly close.

Thanks,
Jamie

Cars:
2000 BMW M Coupe (Gelb)
2001 Audi S4 Avant (Gelb)
 

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In theory it shuld be possible to build a black box which adds some packets to the CAN network carrying the date/time data. That's what those CAN adapters for older cars to (they translate speed, ignition and lights into a CAN signal). But as far as I know none of the CAN adapters available today do this.
 

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Yes, this is a known issue for most of us who have a pre-2002 C5 A6 or B5 A4/S4. The newer (2002+) instrument clusters don't have this issue. I think I've spoken to most everyone on this board with a 2002+ C5 A6/S6/RS6/allroad....and no clock issues.

See my link below for installing the RNS-E in a C5. There is a rumor that you can fix the clock issue by disconnecting your battery at midnight. Give it a try and see if it works (just have your radio code handy).
 

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I just found a thread here that suggests that building a CAN device is not very hard. The discussion they're having is about having video in motion. However, if you can filter CAN messages and spoof others, then it shouldn't be too hard to put time messages on the CAN.

There's probably a request/acknowledgement protocol for time. Does anyone have a CAN analyzer?

Being able to put things on the CAN would also give us B5 owners more flexibility in what RNS-E we buy.
 

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I got a USB to CAN interface and plan to do some logging in the near future. But I'll have to get some other pieces together first. And I have no idea how to get the knowledge into a little black box to do something. :cry:
 

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I have a 4B0 RNS-E in an RS4 (B5) showing the same behavior. The strange thing is, that the time shown in engineering mode is correct.

- Hendrik
 

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schmoell said:
I have a 4B0 RNS-E in an RS4 (B5) showing the same behavior. The strange thing is, that the time shown in engineering mode is correct.

- Hendrik
2nd. In Engineering mode, it shows the correct time in my B5 S4. When calculating the ETA (and in the settings menu display) its wrong. Very strange.
 

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AudiA4B6US said:
I got a USB to CAN interface and plan to do some logging in the near future. But I'll have to get some other pieces together first. And I have no idea how to get the knowledge into a little black box to do something. :cry:
Where did you get the USB cable?
 

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