PCCM Plus - DAB/Radio issues

911-C2 · 24 Apr 2024

9EtS said:
I am starting to expect it may be done differently on a C2 vs C4S/Turbo. The sticker on the passenger side unit states it’s AM FM so we can be sure that it’s the antenna for Radio.

The loop on diversity unit is expected to deliver a joint signal from the two antenna stickers on the windscreen, via the passenger A pillar receiver which in thesis is based on what I’ve seen of the pccm+ install guide pages.

From how it’s been done, it seems to have been an OPC job, as it’s exactly as per the manual so far.

This p/n is aerial booster which is eaxactly what you are supposed ot bypass - I threw mine away

911-C2 · 24 Apr 2024

9EtS said:
Left.

Where does this cable go?

IUI675 · 24 Apr 2024

9EtS said:
From how it’s been done, it seems to have been an OPC job, as it’s exactly as per the manual so far.

It clearly isn’t done per manual, because the module bypass is plugged into the side of the module.

Bypassing the module on the wrong pillar might explain why some of us had to swap the wires around in the footwell.

Fwiw, mine is a 2003 c4s.

911-C2 · 24 Apr 2024

IUI675 said:
It clearly isn’t done per manual, because the module bypass is plugged into the side of the module.

Bypassing the module on the wrong pillar might explain why some of us had to swap the wires around in the footwell.

This is true and good point. Its just a coax cable, you can buzz it out from aerial to back of radio and confirm its coninuos ocnnection. My DAB+ only worked standstill until I did this.

911-C2 · 24 Apr 2024

Disconnect this brass connector from this booster and connect to the silver connector should be the fix. Right now amp isnt bypassed and there is an "air gap" to stereo it woudl seem. Good old OPC..... no clue.

IUI675 · 24 Apr 2024

Next time I get a quiet moment, I’m going to go swap the bypass to the white module from the black and see if the dab reception gets better or worse. I am wondering if it’s currently wired up to the gsm aerial! 9ets is correct, the white module clearly says AM/FM on the side.

911-C2 · 24 Apr 2024

IUI675 said:
Next time I get a quiet moment, I’m going to go swap the bypass to the white module from the black and see if the dab reception gets better or worse. I am wondering if it’s currently wired up to the gsm aerial! 9ets is correct, the white module clearly says AM/FM on the side.

Looks like depends if you have PCM from factory, but the part numbe ron the one on RHS matches p/n 26 and the wiring diagram matches what I have for sure.

911-C2 · 24 Apr 2024

Missed that, left and right although not both shown on drawing. Left would be better as shorter cable run I guess.

9EtS · 24 Apr 2024

The large silver (free) connector and large golden connectors are the same size, also in effect that would create a loop.

Tested after every change below, if the white module is taken out of the equation there is additional hissing whilst the symptoms persist.

- connect aerial inbound small gold to larger silver (feeds into diversity box)
- connect aerial inbound small gold to larger golden (feeds into diversity box)
- change aerial tag supply from left of the white module to right with above changes
- disconnect everything from the white module to my surprise it still works with the same set of problems but that just tells me that the wire is able to recv signal without the module or something else is actually providing the signal (albeit the diversity module loop removal does break the service, so there is something more to this)

I don't know what the car had before this was upgraded. I am going to look for my multimeter from back in the day and have ordered trim removal kit.

A Porsche specialist who is scheduled to perform an assurance inspection on the car next week told me they can resolve this problem.

IUI675 · 24 Apr 2024

The goal is to bypass the white module and bypass the box in the footwell.

Connect the two gold connectors together, see if it works. If not, swap the connectors on the plug in the footwell.

The symptoms your describing are the same as when the aerial wasn’t connected in my car and it was just using the wire between the head unit and the footwell to receive dab.

911-C2 · 24 Apr 2024

IUI675 said:
The goal is to bypass the white module and bypass the box in the footwell.

Connect the two gold connectors together, see if it works. If not, swap the connectors on the plug in the footwell.

The symptoms your describing are the same as when the aerial wasn’t connected in my car and it was just using the wire between the head unit and the footwell to receive dab.

Yep the idea is to bypass everything as the original modules have attenutors in to specifically block DAB+ and only allow FM/AM frequencies through. Im convinced now doesnt matter if you do Left Side or Right Side, indeed Left Side will be superior as shorted cable run for htis higher frequency DAB+ signal.

9EtS · 24 Apr 2024

IUI675 said:
The goal is to bypass the white module and bypass the box in the footwell.

Connect the two gold connectors together, see if it works. If not, swap the connectors on the plug in the footwell.

The symptoms your describing are the same as when the aerial wasn’t connected in my car and it was just using the wire between the head unit and the footwell to receive dab.

The diversity module loop is definitely functional, removing it = signal down. Relocating it to the other port (wrong port image as per your original post pic is not possible because the loop cable endpoints won’t sit in.)

I bypassed the white am-fm module by connecting the antenna small gold pin to large gold / large silver but nothing changes.

9EtS · 3 May 2024

Update:

Upper antenna port to amplifier / HU cable replaced (faulty, but wasn’t the root cause). That is connected to the brass/gold cable directly.

Brass/Gold cable ( and silver ) rolls back to Diversity Module.

Removed Diversity Module and moved loop to connect the brown/purple headed cables. Image shows old connection - should not be that way.
UK RHD, passenger A pillar.

White end cables left disconnected.

All Radio / Tuner / DAB+ services fully functional

Thanks @IUI675 @911-C2

Claudioso.ga · 10 May 2024

Hello guys I write from Italy I installed the same system on my 996 4s and now when I listen radio, Navi, Bluetooth or via usb cable, I ear a bip under the music or Navi instructions and I don’t know why, nobody had this problem?
Thank you so much

9EtS · 10 May 2024

I had those beeps before having the radio antenna solution applied. They seem to have disappeared.

What is your cabling setup ? Left or Right pillar etc. do the beeps go away if you disconnect the diversity removal loop.