Any help on replacing the PCM unit with an aftermarket head unit?

[Smeg Head]

Hi All

Just starting on my Porsche journey and become the proud owner of a late 2002 Boxster S :thumbup: , my issue is with the PCM 2 unit.

I spend a lot of time on business calls in my car and unfortunately the PCM isn't going to work for me; I have a new T-Mobile contract, they won't do a duplicate SIM for the car, and apparently it'll cost me about £400 just to get out of it.

Popped into Halfords to look at Parrot Bluetooth devices and came across the Pioneer AVH-2400BT which will do lots of extra wonderful things, except swap easily with the PCM unit already in the car.

There seem to be a few different opinions regarding changing them over, one of which is started by a lot of sucking air through teeth and telling me I "shouldn't be going there", and others that say "yeah, I can sell you a cable that'll do that". I think it's somewhere in between but can someone give me some advice where to get some definitive answers from?

I've read a few articles but they all seem to refer to the single din head unit removal rather than the unit I have.

Am I best trying to remove the amp and PCM unit entirely, re-routing the speaker cables to the new head unit? If I do that will it have an effect on the OBC (obviously I won't have the option of seeing audio details on the central display), someone seemed to think that it's all linked up and things like my odometer wouldn't work properly?

I am on a budget so can't throw loads at this and any help would be greatly appreciated.

Smeg

[whall]

Check out this link:

This is a link that covers the installation of a Pioneer AVIC-D3.....a double DIN nav/radio/music system. The D-3 is several years old now, but the installation instructions are illustrative of the procedure you would most likely have to follow to complete a change of systems.

I am not familiar with the Pioneer AVH-2400BT or PCM2, but have installed a Pioneer AVIC-Z3 in my 2002 Targa (with Bose) using (most of) the above link. There were some minor differences in the physical mounting of the head unit (due to the fact that the originator's car having a slightly different dashboard structure due to the age of the car, not the car model. The electrical power hook-up was identical. The speaker hook-up was different due the fact that my car had the Bose stereo not the stock stereo like the original car. This difference was fairly easy to correct, however. The entire installation was completed without having to make any changes to the car's wiring....nothing was cut. In fact the original head unit could be reinstalled immediately if needed.

The author of the link is very helpful if you were in need of help in installing your AVH-2400BT. He also sells an installation kit which is very handy.

Bill

[Richard Hamilton]

The snag is that PCM2 uses the fibre optic MOST loop to transmit sound and control data between head unit, amp, CD changer, telephone, etc. You can add aftermarket Bluetooth and/or iPod interface devices, but they are quite expensive new. I bought used items on eBay, and spent about £150 for the two.

The alternative is to remove head unit, amp, CDC, phone, etc, and start again. You could connect a new head unit direct to the speakers, but the speakers for Bose systems can be odd impedances, so you would need to check that too. On my 996T I fitted a Pioneer 2-din nav system, and connected direct to the speakers, which I replaced with Pioneer eMotion ones. It sounded pretty reasonable.

[Smeg Head]

Hi guys

Thanks for the quick responses.

Whall, thanks for the link but I think my set up is different, as Richard says mine uses the MOST with fibre optic connections.

Richard, I think this is what I'll end up doing, was there any issue with the displays, does disconnecting the oem kit have any adverse affects on anything other than the unit itself? Mine isn't the Bose system, it just has the dash speakers and the door ones so hopefully the speaker issue won't affect me.

[Smeg Head]

....actually by the sound it seems only to have a sub in the drivers door and nothing in the passenger door

[Richard Hamilton]

Mine was a pre-MOST system, so I didn't have the same issues. You'll lose the radio info, etc, in the instrument cluster display, but that's about the only downside.

The speaker arrangement you describe sounds a bit odd. Do you have an amplifier? If it isn't Bose, it may have a Harman amp, or maybe no amp at all. It would be best to find out exactly what you have before you start. If you drop me a PM with your VIN, I could look it up for you.

[Smeg Head]

Thanks again, PM sent

[Smeg Head]

...and there is an amp in the front luggage space (boot?) but I can't see any marks as its covered by the housing

[whall]

I also have a MY03 Boxster (with MOST bus and boot mounted Harman amplifier) in which I installed a Pioneer AVIC-Z110BT....again using the installation kit offered by the author of the above link. I had to do the following to resolve the problems associated with the MOST bus:

1. I pulled the Harman amplifier and wired the audio output of the AVIC-Z110BT directly to the speakers. (When the Harman was removed, I inserted the audio output wires directly into the plug left empty. I used individual miniature "banana" plugs. Again, no cutting of stock wiring....immediately re-convertible to original configuration if required.) I know I loose points for depending on the anemic power output of the head unit instead of having an amplifier with enough power to light a small city. However, the much improved sound of the new head unit is loud enough for me.

2. I had to run a wire for a switched power source to the fuse panel that would keep the head unit powered until the ignition key was physically pulled out of the ignition switch.....like the stock radio setup. I initially tried to use the switched power source that is part of the optional telephone system (possibly found in US cars only(?)) but found that that source was switched off as soon as the ignition switch was turned off. The continuous (keep memory alive) power source is taken care of with the wiring harness provided in the installation kit.

There is a link to another RennTech Board member's MOST installation in the 986 Boxster DIY section.

Oh, the OBC in my car works well indicating all of the car information as indicated in the Owner's Manual but nothing for (or from) the haed unit.

Bill

[whall]

Here's the MOST bus link I mentioned above:

Bill

[Smeg Head]

Thank you Bill, that's very helpful and it sounds exactly like the way I want to do it, I'll keep you informed and I might contact you again if I have any questions if that's ok, Smeg

[Nimbus117]

It's not an easy undertaking - be warned! I have a 2003 model too, apart from the speakers - the rest is useless. I did however get £200 on ebay for the head unit, amp and cd changer which was good.

The guides will show you what to do. I bought the rear speaker kit from the US as also the trim surround from a guy off here - would recommend you do the same as every other trim surround looked cheap and it sounds 10 times better with the extra speakers in the back.

I got a live feed off the aircon unit, I bought a couple of ISO plugs and sockets off ebay and rewired it to iso standard to connect to my Pioneer 930BT. The ipod adapter is routed to inside of the arm rest, I often use TomTom on the Pioneer in app mode from my iphone and I get good satellite signal even from inside the arm rest. I would go as far to say - dont bother with a navigation device if you have an iphone. The pioneer unit you are looking at has app mode and is much cheaper than my unit - TomTom is much better than the Pioneer software offering.

Buy a decent amp (Alpine) to run the subs, I had awful alternator whine with the first one I bought. I ran the front and rear speakers off the headunit which sounds great. Routing one pair of RCA cables was much easier than with 3sets for the 3 way amp I first tried.

While you are at it, go for the reversing camera while you are at it. If you want any advice, send me a PM.

Richard

[Smeg Head]

Hi Richard

Thank you. I was planning to do the rear speaker install and to upgrade the dash speakers, I was hoping to get away using just these and therefore not requiring an additional amp?

Does anyone know if the cabling for the rear speakers is already in place? I was chatting to a chap at the weekend who suggested they'd be there but just taped up if they weren't being used, he seemed to think they would use the same harness for every car, whether the options were fitted or not.

Smeg

[whall]

Unfortunately, the chap is incorrect. There is no "standard" wiring harness for Porches. Every car is buil to specific order requirements. In fact, Porsche doesn't build a car without a specific order from an end user......either a dealer or a customer.

Bill

Edited May 8, 2012 by whall

[Smeg Head]

Unfortunately, the chap is incorrect. There is no "standard" wiring harness for Porches. Every car is buil to specific order requirements. In fact, Porsche doesn't build a car without a specific order from an end user......either a dealer or a customer.

Bill

Doh

[Nimbus117]

Hi Richard

Thank you. I was planning to do the rear speaker install and to upgrade the dash speakers, I was hoping to get away using just these and therefore not requiring an additional amp?

Does anyone know if the cabling for the rear speakers is already in place? I was chatting to a chap at the weekend who suggested they'd be there but just taped up if they weren't being used, he seemed to think they would use the same harness for every car, whether the options were fitted or not.

Smeg

There are only 4 speaker outputs on the pioneer units so used these for the front and rear speakers. The subs therefore require a feed from a pair of RCA outputs to an amp.

There is no wiring in place for rear speakers if you dont have them already. However it is supplied with the rear speaker kit and is the correct length with the correct plug to plug straight into the stereo. It also comes with an extension so you can plug into the Porsche amp in the front if there is anyone wanting to add rear speakers to the standard offering.

[Smeg Head]

Hi All

Well it's done and I'm very happy apart from a couple of issues; one fairly big and one not so.

In the end I decided to do it as easily as possible, and to leave eveything stock so I could reverse it if required.

I bought a couple of ISO kits from Maplins (so I could chop and change if I wanted) and I used the original ISO plug in the loom to supply constant power, and ran a new connection from the fuse box to source switched power to the device. This was the one slight headache as the unit I bought doesn't seem to have a complete "Off", it just seems to stop outputting sound and turns off the display but leaving all the lights on like a Christmas tree (not ideal in a rag top), if I could have turned it off completely I might just have wired them both to permanent live. I also just rewired the speakers using some new cable and a few spade ends, again so I could just unclip the original wiring and leave it in place in case I wanted to put it back.

I haven't used it much yet but so far I've been surprised by a couple of things. What's good: Absolutely love the Pioneer, much better sound even using just the the stock speakers in the dash, not even wired up the door sub. I love the fact I jump in the car, turn on the ignition, iPhone and unit connect automatically using Bluetooth, unit starts the music app on the iPhone and starts playing the track where it left off last time, I don't even have to take it out of my pocket :clapping:

Another thing is the Satnav on my phone (I have Navfree, I can't endorse the app as I've not used it much, but it's there if I need it), I start the app on my phone and when the nice lady has to tell me what to do, my music volume lowers and I get "Turn right at the next junction" or whatever direction I need...who needs TomTom?

I read there was a additional cable you could buy to hook up the iPhone if you need more facilities than the Bluetooth but I didn't bother. I did want to see if the USB would charge the phone though so hooked it up and it does, I think. The reason I say I think is because I forgot to look, as soon as I connected it I noticed USB source had control over the iPhone...I could use the unit to scroll through my music, album artwork came up on the display, what extra's the cable gives you I don't know.

The only really bad thing is I can't get a radio signal using the Fakra connection in the Porsche. I bought an adaptor (Google PC5-111) and hooked it up to the black Fakra connector but didn't get any signal to the unit. I then tried an amplified version (PC5-137) connecting the blue cable to the blue cable coming from the ISO (connected to the white cable on the original Porsche loom) which I believe is the powered antenna control, this might be where I've gone wrong and would be appreciative of any correction. The other slight issue which I actually thought I'd have to rectify anyway is the slightest of gaps around the facia, maybe a couple mm and can only be seen when you get down to the same level as the unit, I think I'll probably live with it.

Thanks to all that helped me and if anyone else stumbles across this please don't hesitate to get in touch if you think I can help.

Smeg

PS: Anyone want to buy a PCM 2 unit with Sat Nav? :)

[Smeg Head]

Update....the USB does charge the iPhone :)

Any ideas on a subtle holder / cradle to go somewhere near the head unit, possible near the lighter socket? Want something solid and not tacky.

Still waiting any ideas about the antenna connection, any clues?

[Nimbus117]

What Pioneer unit did you buy? Sure you have wired it up correctly? mine turns off with the ignition. The cable is worth getting as you say, charges the phone, displays album artwork, app mode, video etc.

My iphone lives in the armrest in the centre console as that's where I ran the connector cable. Gets a GPS signal even with a hardtop on, as explained before I use the TomTom on the phone which displays on the screen of my Pioneer 930BT unit in app mode which has more up to date maps than the Pioneer offering (as well being plain better). Dont need to touch the phone, can control everything through the Pioneer.

You might have a dodgy fakra adapter, mine works fine.

[Smeg Head]

Hi Richard

I went for the Pioneer AVH-2400BT which seems excellent. I think the only thing I'm lacking using the USB cable plugged into the front port is the App mode, but I didn't realise it would display the Sat Nav on the head unit, I might have to get one; I presume it will still play from other audio sources as well?

Regarding the radio someone said to me it might be the antenna not being powered, is that a separate power than the blue cable on the iso plug? I've been away so haven't had chance to investigate yet. The adaptor you use, is it the amplified one?

Smeg

[nota911]

2. I had to run a wire for a switched power source to the fuse panel that would keep the head unit powered until the ignition key was physically pulled out of the ignition switch.....like the stock radio setup. I initially tried to use the switched power source that is part of the optional telephone system (possibly found in US cars only(?)) but found that that source was switched off as soon as the ignition switch was turned off. The continuous (keep memory alive) power source is taken care of with the wiring harness provided in the installation kit.

Bill, do you recall which fuse you connected to for the switched feed?

I have just discovered, like you did, that the a/c panel harness just has an ignition-on feed. So I am going to have to run a wire to the fuse panel too.

[whall]

I didn't actually do the wiring. A technician at my dealer did the actual work. I'm in the shop now. The technician says he hooked the power lead to the "86s" / E-1 fuse......but doesn't remember which side of the fuse. He suggests that you remove the fuse and use a voltmeter to determine which contact is powered and then hook up the wire to the other contact thus retaining your fused power protection.

Bill

[Richard Hamilton]

As Bill says, fuse E1 is Terminal 86S, which remains connected while the key is in the ignition. Connect to the top connection of the fuse, as that is the output side.

A fuse tap is the easiest way to make the connection. The photo shows connection to E8, which is also suitable.