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GT3 | Becker TrafficPro Install

Becker TrafficPro Installation

Many thanks to Julian Thompson who supplied the unit as part of a group buy and was incredibly helpful both via email and on the phone. We thought the unit should be a direct swap for the existing head unit in the car but we were wrong! Still, got there in the end :-)

The complication is that it turns out that for the 04 model Porsche have adopted CAN bus technology. I don't have much of a clue about what this means, but it's something to do with using encoded signals to various components rather than using simple switched supplies. So the radio subloom in my dash doesn't have a switched feed for the radio, and a signal from it can tell the car there's a problem and disable the climate control ... more later.

First thing to do is to dismantle the dash. although rather nerve wracking it's actually fairly easy, 911's are well engineered and good to work on. Using a small bladed screwdriver with some insulation tape over the end you need to carefully prise out the narrow rectangular strip surrounding the climate control unit. This is simply clipped in with a single clip at each side about a third of the way down from the top. Here's a pic with it removed:

Sorry about the quality of the pics - dark in the garage in winter! Once this is removed you can see 2 screws at each side - the upper pair hold the climate control unit in place, the lower 2 remove the horseshoe shaped surround in place. Just below the upper screw you can see the little hole in the white plastic that the rectangular peice clips into. I did remove the surround, but you don't really need to - if you need to undo the two screws then the thing unclips. There are two connectors plugged into the back of the climate control unit, these have a small latch and are easily removed. Once it's out of the way you have good access to the back of the radio:

You now need to remove the radio. You either need to use the little tools that come with a Becker unit (or can be bought fairly cheaply from a car audio or OPC), these are inserted into the slots on each side of the head unit towards the borrom. This pushes in the little sprung latches, and you can then stick a hand behind the radio to pull it out. Although the tools do allow you to pull on the unit it's fairly hard to pull out without some assistance from behind.

The head unit is easily disconnected and removed. Next job for me was to fit the GPS antenna. although these are intended to sit on top of the dash so they can 'see' out of the windscreen, Julian said they work OK under the dash, neatly hidden from view. He suggested mounting it on top of the heater vent at the far left side of the dash, so that's the next bit to need dismantling. There are 2 screws in the outside face of the vent surround trim (left pic below), and one hidden under the round blanking plate where the light switch is on a LHD car (right pic below):

You'll need a torx bit to get these out, then the whole trim can be pulled out. Once out you can see the plastic ducting in the upper part of the left hand pic below with a close up of it in the right hand pic. In these pics you can see I've already stuck the GPS antenna on top of the duct using the sticky backed velcro supplied. It just fits in the narrow gap between the duct and the undersurface of the dash.

Fairly simple job to run the cable across under the dash to the centre, the instructions say to tie up the excess length of the cable at the antenna end rather than the head unit end, so that's what I did. The next job was fitting the microphone - this is used not only for the handsfree phone facility, you can also control all functions of the unit with voice commands. Allegedly. I was fairly worried about this bit but it was easy enough. No pics as there was nothing really to take a pic of! The A pillar trim is a one piece unit extending right to the back of the top of the door. It's clipped in, and the first stage is pulling the rubber door trim away across the top of the door surround and down the A pillar. Then you can carefully get a couple of fingers behind the trim at the front top corner and gently ease it out. You only need to ease it out enough to push the microphone through from the outside as the wire can then be run down in the gap along the outer edge of the trim and the rubber edging strip replaced. Then you need to burrow head first down the footwell to get the wire across under the dash and make sure it's secured with cable ties.

Once all the trim is resecured it should simply be a matter of plugging everything in. But it wasn't. First problem was that the aerial connector on the new unit was different to the one on the old one. Solved that problem at my local car audio emporium with an adaptor for a BMW 5 series, with an adaptor for that to fit to the ISO connector on the car loom.

Plugged it all in and connected up and it all just worked. Trouble was that it wouldn't come on and off with the ignition, it was independent, which was a bit of a pain. Also, when the ignition is turned on the climate control unit doesn't come on until you switch the radio on. Turns out this is down to the CAN bus electrickery.

After posting a question on the RennTech Forum I was advised to cut the wire from the radio loom which sends the dodgy signal back to the CAN bus and take a switched feed from the climate control unit.

Rather than cutting any of the car's wires I got a Vauxhall adaptor lead which basically provides an ISO to ISO connector for both the power connector and the speakers. The speaker connector wasn't needed so I cut it off and cannibalised it to get a couple of extra pins to connect on the power connector. The TrafficPro requires inputs from both the speedo and the reversing light, fortunately these were both already wired correctly. The permanent 12 volts was also correct, as was the earth. The wire to pin A5 on the TrafficPro seems to be the one which disables the climate control, and disconnecting that did the trick. I soldered a fly lead with an insulated female blade connector onto the blue/black wire in the climate control loom and connected that to pin A7 on the TrafficPro. Success! It now comes on with the ignition and the climate control unit functions normally. Oh no it doesn't! See below ...

The Final Solution

Gary who originally put me in touch for the group buy contacted me to say he'd fitted his unit as I'd done mine, and had had a weekend down at the Ring, and had cooked as it was warm weather and he'd discovered that despite the unit looking like it functioned normally, in fact the aircon compressor wasn't coming on. Further enquiries suggested that the CAN bus could be re-programmed at the OPC, alternatively someone on Renntech suggested that disconnecting the C1 block at the back of the unit would sort it. Unfortunately Gary found out the expensive way that the latter was the correct answer!

So I tackled mine again, unplugging the little connector block labelled C1 on the Becker instructions, I also reconnected the wire which was labelled antenna/amplifier as I'd discovered that this in fact was required to power the aerial amp - with it disconnected reception on medium wave was crap.

This fixed it, and I now have a fully functional unit and functioning climate control ready for June's little trip down to Le Mans.

Using the TrafficPro

Does it do what it says on the tin? You bet! Fabulous unit, so neat to have all the functionality in the one head unit rather than having a separate satnav unit, bluetooth handsfree and something like an iPod dock. And the voice control does work very well. It's better for the commands you teach it yourself, like the recordings you make for radio stations etc., but it's pretty good at recognising its inbuilt commands and numbers etc. The satnav isn't as good as a dedicated unit with a nice map display, like Tom Tom or similar, but I prefer having this to an additional unit stuck in the car. It also comes with maps for the whole fo Europe (unlike the Tom Tom I've got for my SmartPhone).

Home | Links | Contact me
The Build (2003/4): June | July | August | September | October | November | December | January
Updates: 2004 | Le Mans | Sold | New Project
GT3 | Becker TrafficPro Install

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