MK1 C4P RT4 Aux and USB input?

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.

Moderator: RichardW

Donor 2021
Posts: 6
Joined: 09 Jun 2021, 12:07

MK1 C4P RT4 Aux and USB input?

Post by TawhidAhmed »

Hello All,

I have recently bought a C4 Grand Picasso with the RT4 Navidrive unit. I was wondering how to add an Aux input and USB to this system. I understand there is an Aux lead that can be bought that plugs into the back of the system, however, it appears this port is already in use! But by what? It seems to be part of the main wiring loom for the nav unit. I am not sure what to do. I have attached some pictures to show the port. The leads I found online are like this: ... SwJshdh13L
User avatar
Forum Admin Team
Posts: 25121
Joined: 15 Sep 2015, 19:38
x 2773

Re: MK1 C4P RT4 Aux and USB input?

Post by GiveMeABreak »

On the back of the RT4 unit look Part 'C' in the diagram below. That is where the CD changer port connection would be. So if you don't have anything in there that is where you would connect a USB.
RT4 CD.PNG (54.55 KiB) Viewed 14 times
In your last photograph below where I have arrowed in Red, I can see a wiring lead at the back with a brown plug - which looks like it may be for the CD Changer (when fitted). The CD Changer is installed in the upper right glovebox storage unit, but was not fitted at factory according to your VIN. SO this may be the pre-wiring for a CD Changer to make it easier to retro-fit later.