RT4 not saving time / date + other issues

This unit is the RT4 and RT5 system and is made by Magneti Marelli
Main differences between RT4 & RT5 - RT5 has Bluetooth Hands Free, faster Navigation calculation and on C4 & C4 Picasso only, USB ports and a High-Res screen.

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chris85
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Joined: 04 Mar 2024, 19:44
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RT4 not saving time / date + other issues

Post by chris85 »

Hi and sorry for another request for help... :oops:

Everything was working great so far with the Citroen C6 and the changed RT4 unit. Until today. The RT4 won't remember the date and time. Once the settings are saved and the motor is turned off, the data is lost (once the car and the RT4 starts again it shows a completely wrong date in 2000 and a wrong time).

This issue comes with some other new problems that maybe have to do with a fuse that I had taken out today for some reason... after it was put back, this stuff happened. I am not sure if "fuse" is the right english term, online they call this specific one "shunt". The instrument cluster of my C6 is working some time without any problems, but sometimes it's not showing anything for days (I will send it to a repair service soon). Some people online claimed maybe just the "shunt" is the problem. So I took it out to check it... once it was put back in, the RT4 problems were present. PLUS some other stupid and annoying stuff (I was not aware that this "shunt" could be so important at all) - the side mirrors will not turn out anymore once the car is opened, only when the motor is started they will move. Before this they always turned out when the car was opened. Then only the drivers door unlocks, all other doors stay locked. They will only open when the childlock is pressed twice(!). And when the motor is started the windscreen wipers will move once (no matter if activated or not).

This all is happening after the short removal of this one fuse ("shunt" - which by the way is not defective at all). Any ideas for this or how to get things sorted?

And again sorry for my poor English - maybe some of the terms are not correct, but I hope you know what I mean. Thanks as always!!!
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GiveMeABreak
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Re: RT4 not saving time / date + other issues

Post by GiveMeABreak »

You need to be aware that the SHUNT fuse should not really need to be touched. It has 2 positions - showroom mode and customer mode depending on the position it is placed.

It's use in showroom mode was for the dealership to have the vehicle on display to the public (or when it leaves the factory and is parked up for some time) so that various vehicle systems are disabled to save energy consumption when the battery won't be charged up. So some systems will not work or will have permanent power cut off.

You must always leave it in the 'Customer' position so that power is re-enabled to all systems. In this case if you have put it back in the wrong position you will have issues.

If you have removed the Shunt fuse, then if your RT4 backup battery is low, the settings will not be stored and you will have to reset everything again. But no point in doing this unless you are 100% sure you have the shunt fuse in Customer mode.

It should be Fuse F16, but make sure it is not in the 'Park' or 'Parc' position. You may need a torch to see the writing, but it should be marked.
Please Don't PM Me For Technical Help

Marc
chris85
Posts: 7
Joined: 04 Mar 2024, 19:44
x 2

Re: RT4 not saving time / date + other issues

Post by chris85 »

Thanks for your fast reply! I am such an idiot... the shunt was on the wrong position! I thought I'd put it back the way it was before... but seemingly it was in the showroom mode then (I was not aware of those modes). Once put in the correct place (customer mode) everything worked normal again. I will NEVER touch this shunt again, never ever. :D Now the doors open, the mirrors move and also the radio seems to be able to save the date and time (the RT4 battery was at 100% all the time though).

But thanks for your help - without your input I would still not know what the problem was. So thanks again!!!
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GiveMeABreak
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Re: RT4 not saving time / date + other issues

Post by GiveMeABreak »

No problem :rofl2: Sometimes it's the smallest things that cause the biggest problems!
Please Don't PM Me For Technical Help

Marc