Good morning everyone!
Premise: the original car was equipped with the 3.6 engine (2006). A friend found a crashed car with a 3.8 engine (2008) and PDK gearbox and thought about doing the swap.

The cockpit wiring is the original one.
The cluster, PDK control unit, selector lever, engine control unit and all engine compartment wiring is from 3.8.

Thanks to your help I managed to create the missing part of the wiring that goes from the PDK control unit, to the selector lever, to the instrument panel and to the PAS control unit. The CAN bus is connected.
The engine control unit and the cluster were mounted without any modification.

There are two problems:
1. With the ignition off, the dot appears on the cluster indicating the position of the selector lever.
If I move it, the dot moves accordingly (I think this communication between the selector lever and the panel is operated via the "data" wire with serial protocol).
However, if I turn on the ignition the dot disappears (I think that at this moment the communication takes place on CAN-bus and no longer via serial, or not?).

2. If I try to start the engine it starts but turns off after 2/3 seconds.
In that short time the cluster indicates the engine rpm and by pressing the accelerator pedal, the engine revs up.
But right after that it feels like the power is cut off.

My friend has a Texa tool with which he tried to do an error reading.
The strange thing is that he can't connect to the engine control unit.
Yesterday I checked the CAN bus from the furthest point (the Gateway) to the engine control unit, but I found no interruptions or short circuits.
In fact, the cluster reads the engine rpm and if the CAN-bus were faulty, this would not happen.

I know that the OBD is not directly connected to the CAN-bus but the communication goes through the Gateway (which is the original one).
Could it be a Gateway problem that needs to be reprogrammed to manage the PDK control unit and the engine control unit of the 3.8?

The VINs, from what I was told, have all been updated (with the Texa?) but I don't think it was possible to also update the engine control unit, if apparently it doesn't communicate...

In your opinion, is it absolutely necessary to connect a PIWIS and start rearranging the configuration of all the control units?
Can only PIWIS do this?

Sorry for the long post and also sorry for my bad English.
Best regards.
Federico.

 

little update, if anyone has any ideas to suggest.

when the engine starts, by spraying the starting spray at the same time, the engine continues to run.

could it be the engine control unit that inhibits the fuel pump (protection strategy) or could it be a problem with the high pressure pump?

given that the control unit is working with a gateway that is not its own, could this be the reason why the engine turns off?

Thanks

 

...or could it be the bcm module (which is original)?

 

Hi Federico, sorry you're not getting too many answers so far. I wish I could help, unfortunately I have no applicable experience. I'm cheering for you!