Correct. How accessible is the plug on the control panel? Be sure to pick the correct purple wire (I see there are two) I'm worried that you have a permanent short to earth inside the panel or on the wiring between the panel and the ECU. It may override any attempt to return the back of the seat to the upright position. Disconnecting the panel and putting an earth on the green (or purple?) wire will take a faulty control panel out of the "equation".
The “control panel” would be 7M, right? Would we access that from the seat bottom side or should we remove the tilt lever and access it from there?
This advertisement has some good pictures of the control panel. https://picclick.fr/Ferrari-456M-456-M-Gt-Si%C3%A8ge-LUnit%C3%A9-DExploitation-274393498231.html Unfortunately, all the wires going from the panel to the plug seem to be white, making it hard to identify them.
Yep, the wires are quite long, looks like it’d be best to access from the seat bottom side. As regards the earth signal that needs to be applied, I assume that the seat tilt movement sequence is as follows: The tilt lever is connected to the panel, the panel plugs in plug 7 - plug 7 sends the signal to the ECU - the ECU activates the motor - the seat tilts. If this is right, I guess we would need to apply an earth signal to pins M (in the diagram) of plug 7, hence not on the control panel but on the actual plug (the “female” plug, where the seat control panel plugs in). (?) Or, as a second option, apply 12V power to the motor (hoping that this attempt won’t be overridden by a permanent short inside the control panel). Disconnecting the panel doesn’t seem viable to me, as it would kill all the seat movements…
Correct. If you can't find a good earth on the seat, use pin 3 on the same plug. If you disconnect the motor plug and apply power to the motor, this will stop any false signals reaching the motor from the control panel. Can you disconnect the control panel and try operating the easy entry controls? All the panel is doing is providing earth signals, which you can do with a jumper wire on the appropriate pin of plug 7. Of course, if you have the panel disconnected, the other buttons won't work.
I just noticed that there are wire colour differences depending on which Ferrari manual you look at Here's one on the ECU (the wire goes to the motor plug 6M) Image Unavailable, Please Login
Apart from a faulty control panel, you could have a short to earth on the seat (back) tilt forward wire (green or purple?) at any point between the control panel and the ECU and you will not be able to put the back of the seat to it's proper position. It would be good if you can determine which wire does what (purple/green)
Hi there Ian (and whoever else is following this post Thought to update. We gave 12 V on the motor: the back rest moved for about a second then stopped (tried a few times). The wire that goes from the motor to the back mechanism did tense when we gave power. It all makes us think that this issue is mechanic rather than electric. Guess will have to turn to a Ferrari garage.
Updating again with good news. The problem was solved (thanks to Ian - Qavion who was our polar star). The trick was to disconnect the seat ECU before giving 12V to the motor pins. I attach a pic detailing the seat recline pins to give power to. The crazy thing is that not only the recline is back to normal but the seat tilt lever works again too ! Thanks again, Ian ;-) Image Unavailable, Please Login