TDS

Hi,

I've just retrofitted pcm 4 to my 958.2 Cayenne after following the other thread in here, I'm almost there but I need some advice with the coding.

I already had the multifunction wheel fitted but unfortunately with the pcm 4 connected the volume control wheel is not working, instead the volume is changing when I scroll using the cluster menu on the right hand side.

​​​​​​There must be a software issue because I know this works with the 2016 /17 cars. Any ideas ?

The second issue is that I've lost the park assist display on the pcm, the sound is there but no display.

Hoping you guys can help me out.

Thanks

volcanogts

Can you elaborate on this swap? I really want to retrofit the pcm4 with factory carplay into my 2016 GTS with pcm3.1, I thought there was all kinds of bench programming and computer coding of the radio itself to get it to work?

In regard to the steering wheel, there is coding in the steering wheel control module that you can code and it will swap what does what. I’ll have to find it, I think I explained it in one of my posts retrofitting a heated wheel to my 2016, at first the controls didn’t work, similar issue you describe and then I changed one line of code and it worked properly again.

volcanogts

Found it, yes, you have to go into the steering wheel control module and swap the communication protocol. There are only two options, so pick the other and you should have your controls back.

What year cayenne are you doing this on?

TMC.

I have to do this!

TDS

I'm planning a full debrief once I get everything done but it's possible. You need to find someone to flash the sw to remove component protection and enable CP/AA. That's the easy part I made a customised harness so it was plug and play.

The thread for the 991.1 is the guide I used but it does take some patience and trial and error because not everything has been documented.

Thanks very much, I'll take a look today I couldn't see the communication protocol in the menu maybe my steering control module is too old. Do you have to be in developer mode and is it in German? The car is a M/Y 2015 958.2.

Thanks

volcanogts

I was able to do the coding with my launch x431, so English and not developer mode

TDS

Thanks, that option isn't there for me with PIWIS III so I have purchased the module 95b959256E to replace my 95b959256 which has an older software version. Wish me luck!

volcanogts

That’s a bummer it didn’t work. When I got my new module and installed it, I didn’t have to do any coding changes at all, it just worked. At first when I installed the wheel with the existing module heat wouldn’t work and the buttons were reversed, I changed that bit of coding and the buttons worked but still no heat. When I replaced the module with a new one it all worked with no coding. It does have to be a new module though, not used.

rainer

Yes, you have to go for a new module. Don‘t use a used one.

When I retrofitted heated steering I already had that same module in place, same part number.

it took me weeks to find out that it worked with a new module, even though part numbers were identical.

for heated steering actually easy to find out: if it shows an error under actual steering temperature, module does not work.

When you go for systematic error evaluation, you can use Piwis very nicely: look at actual values and also look into the activations section. There you can test each switch step by step and see if the module works and how.

TDS

Oh dear Rainer, I bought a used one but the part number and software is a later revision so I had hoped that it would play ball.

Why won't the used one work with some coding?

rainer

You might be lucky it may work - or not.

swap it in and test, use actual values and test to see if it does what is supposed to do.

all I can say is that my stock one with the „E“ at the part number did not work, same number but new did with heating.

you will find out…

TDS

Guess who got lucky.... I replaced the module with the E part number dated 10.2015 and a new option appeared in coding under byte 3 in the steering wheel electronics area. I changed it and although the volume control was now working, I had the same problem as it was also controlling the cluster, just as before! Thankfully I didn't give up.

I then tried to code the cluster again to see what I was missing and there was an option to code the MFL to gen2. I did that and it worked!

Thank you everyone!

volcanogts

Thats great news! So is your PCM4 now fully operational? Are you able to code and change the welcome screen from cayenne to cayenne GTS or turbo or whatever?

twodollardoug

Ok wait a minute. What are you guys doing? Putting a later model pcm in an earlier car? What years are you guys working with?

TDS

Yes fully operational except the park assist graphic on the screen but I'm working on that.

Yes that should be quite easy to code.

Not an easy task and probably even more difficult on a .1 car.