Front Parking Sensor and AE with Custom Buttons

[PawnSacrifice]

This is a bit rambling, as it my way, but the pictures should give you the general idea if you can't be fussed with the text. It's something a little different - check my switch.

PVR posted… Installed parking sensors (non BMW) which set me thinking about using this as a front parking sensor for the Z4.


Also, a little while after I saw gookah's AEs in Hellooooo from a new member I decided I wanted to get that done too (I know it's been done before).


Bought both and set about thinking how to make it all work. As always I wanted everything to look and work as OEM as possible.
The parking sensor was quite simple, I just needed to make a switch that looked OEM.
The Angel Eyes, I spoke to someone at Cooper BMW about how theirs worked as DRLs. I was told that for DRLs (rather than additional lights) they used brighter lamps and that they could be set to default to on or off on the dash. So check on the brighter bulbs (CCFL) and ? about the on and off default. I always wanted to override the default setting, temporarily. Using these as DRLs I wanted to use them independently of the main lights, so needed another power supply and switching.

The AEs have been done now, so I'm not going to write that up - thanks to gookah who sent me excellent instructions when I asked about where he bought his. This is a post about the parking sensor, wiring and bespoke switching.

Before I forget, thanks to everyone who helped me with my Some numpty electrical questions.

 

[PawnSacrifice]

AE Wiring
First I needed a switched fused power - I didn't want these things to stay on when the car was turned off. After speaking to the guys on here, checking the BMW WDS I had a chat with one of the guys at Grosvenor Motors who suggested using the switched supply for the radio. Using the Petach method I finessed out the air vent and found the switch power supply - pin selection on the WDS.

Having wired everything up in my living room to a 12V supply, I confirmed the whole setup was using just a little over 1amp (including starting the CCFL inverter. So safe.

I followed the supply back until I got a decent sized cable. Thankfully BMW had a bullet connector that I tapped into.


I then wired up the AEs to the power to check they worked okay - just robbed the neutral supply from the cigar lighter - and make sure it didn't blow any fuses.

All went well.

I removed the pedal cover in the driver's footwell and found found a large rubber grommet (for want of a better term) that went from the cabin to the engine bay. I pierced and unused section and fed the cable through - power, and cable for the PDC.


I found the correct length for the cables, running along the main loom, cut and then wrapped with loom tape:


The AEs were already fitted to the lights, the inverters inside and the power cables threaded through a small hole and sealed with silicone. These went into a waterproof plug - very tight fitting. For the power side I used the cable taken from the cabin and took the neutral supply from the main lighting loom.


I fed another length of wire for the power through the bumper to the passenger side and connected as before, taking the neutral supply from the exiting light.


Just a not, I cut into the cable sleeve, wrapped the new wire around the existing and then crimped them together. They were wrapped in electrical tape to re-seal and then loomed.

I tested everything again, several times, to make sure the AEs were going on and off with the ignition, and then fitted the lights to the car.

 

[PawnSacrifice]

Park Distance Control (PDC) Fitting
Having already taken the bumper skin off I cleaned the back with alcohol and then applied the electromagnetic sensor strip supplied in the kit - this is self adhesive. It is fitted at the part of the bumper that sits furthest out.


Because the metal bumper sits close to the centre I covered the back in duct tape - black, as silver tape has metal in it. Also made sure the connector was on the driver's side


The cable supplied with the kit wasn't quite long enough to do what I needed so I used the cable I fed through previously and fitted a spade connector to the end to match that on the kit.

This was taped up before refitting the bumper.

The other end of the cable was connected to the supplied kit using another spade connector. I stashed the control unit in the side of the footwell and Velcro'd the beeper to a cross bar near the steering column.

Switching aside, that was pretty much it. The kit normally runs off the reversing light - just wire in the +/- cables to the respective light connections. In this instance I needed to connect to a switch off of the main supply.

 

[PawnSacrifice]

Switch
This is the interesting part. I needed to come up with something that looked, felt and behaved OEM, for both the PDC and AEs. Thanks to Z4 Beemer and Oakandacorns who got me looking at the main console switch panel, I dismissed it. Here I would need:
1. The buttons had to look the same as the existing one - size, shape and backlighting with OEM style labels.
2. Buttons that would have a tactile push, on and off - rather than a locking switch
3. They would need to reset if the ignition was switched off and on again - like the DSC, fog lights, etc.

Making the buttons.
I dismantled the switch panel, taking out the buttons and holder, splitting them down to their component parts. Set these in a silicone rubber mould. Fill the mould with liquid plastic, leave to set and then remove.



I had to do this a few times to get something I could work with. This is still relatively new to me.

I cut out the buttons and sprayed with an acrylic model pain - had to mix black and white to get the right colour. Again, took me a few goes to get a match. I then used a small point screwdriver and a wash as a guide to etch out something resembling the BMW light symbols with an AE add-on and a PDC symbol.


Behind the BMW switches are small circuit boards, obviously I needed to make my own. I cut a strip of circuit board to size and used a small momentary (only makes a circuit when pushed) tactile switch for the button (not as much travel as the BMW ones ). I added the back light LED - I took this off some moody orange LED indicator light I bought off eBay, that never worked, with a resistor attached. There is also a second LED which is the on / off indicator. This was red for the AEs and Green for the PDC in the end.

From my lab / living room tests, I found that the tactile switch didn't work consistently - either many times in sequence or not at all. For some reason I decided to fit resistor, this solved the issue. This is all new to me - I've never made a circuit board before or even soldered for that matter.

I was very careful to colour code all of the wires coming off the back of the switch to go into the connectors.

I used two connectors. The first was for the back light LEDs, I connected these to the supply for the small LED by the cigar socket in the ash tray. This mesa that the back lights dim and brighten with the rest of the dash, again info from the WDS.
The second connector handled the operating LEDs and two wires for each of the switches.

Front of the switch with the new buttons in situ:


To re-fit the front of the switch I needed to drill some holes. BMW, as they often do, kindly marked out the holes for the heated seat buttons, but not the one in-between it and the run flat indicator. I used masking tape to work out the position of the holes and then set about making a mess. Thankfully it paid off…


The front of my modified switch panel.


The switch was then fitted to the back of the console. Wires obviously tidied. Not sure how well it can be seen, but I needed to cut a hole into the back of the switch so it can pass over the connectors if I ever need to.


That covers the look and feel of the switches. Next, the operation. I needed the switches to operate on single pushes, on and off. This took some research, but I found Flip-Flop relays. This uses a push button to operate the relay between open and closed - the tactile switches. Here are the Flip-Flops for the PDC and AEs in there cases - which I had to cut down and weld to fit under the dash.

The Flip-Flop has two power inputs, one for the relay Normally Open (ie you need to push the button to make the connect and turn on the power) and the second Normally Closed (the power is on by default).
For the PDC I connected the Normally Open power supply, the button push tuning on the PDC.
For the AEs rather than wiring the power supply into either Normally Open or Normally Closed I sent it to a switch. One connection went to Normally Open, the second to Normally Closed. This allows me to choose which state I want the lights in. At the moment they are new and novel so I was them on all the time, if later I want them off by default I simply flick the switch, located to the left of the base of the steering column.

For both relays I removed the LED indicator with a soldering iron, replaced with cables and wired these through to the corresponding switch.

Also, the relay resets when the power is cut, so turning off the ignition returns the switch to its original state.

Next job was to wire the lot into the car. Started as a mess, loomed and then hidden.

 

[PawnSacrifice]

Installed


With the lights turned off, ie no back lighting, the buttons glow light up when pushed. The AEs red, to show that they have been turned off from their default state, and the PDC green, to show operational.


With the backlighting on:


That's about it really. Quite a lot of research and work, something I enjoyed doing. I don't think it's something people will be copying in a hurry, but I'm glad I did it.

Picture of the AEs on the car:


Also made a small clip to show the PDC in operation…
[youtube]A3bVNDr3YlE[/youtube]

The PDC fit could easily be done with a hidden rocker or push switch, rather than the shenanigans above. Testing the PDC, it's not great, but for the money and the fact that it isn't visible, I can live with it.

Couple things I want to sort at some point, the PDC button isn't perfect and the beeper is a little shrill, may try and get a softer speaker.

Like I said, some or bits of this have been done before, so thanks also to the pioneers that went before. Hopefully this will bring something new to the table.

 

[Hotride]

I really like the angel eyes gives it a more modern look. I think I will give them a go if i ever find some clear headlights. (my g/f saw a pic of CJ's headlights and told me how much better they look then mine lol)

and the custom switch panel is excellent, i know its something i would not even attempt, and it looks very OEM. impressive!

 

[billygilly]

One of the most ballsy things I think I've seen on here with that level of OEM finish.. I'm sure when it goes in for service the BMW engineers will be scratching their head to whether their real or not.

Still confused to why they werent a tap from sidelights or something which would make them controllable but i'm sure you've thought of all your options alot and this suited you

 

[Taz]

very nice job, the switches look very good, very OEM

 

[playalistic]

Amazing work and attention to detail. Going the extra mile with the OE styled buttons definitely paid off

 

[aquazi]

Omg you have done it again... That's damn impressive, first the seat cog and now this:bow: could you fabricate a supercharger for me?!
How do the buttons feel compared to the stock ones?

Would be good to have been able to link the parking sensors to the speed sensor so they automatically go on under say 5Mph.

 

[ga41]

 

[gannet]

wow, very good job, looks great

 

[navid.v]

wish I was this clever :headbang: brilliant job

 

[PawnSacrifice]

Thanks all

Typically over engineered, but very happy with this "little" project.

Still confused to why they werent a tap from sidelights or something which would make them controllable but i'm sure you've thought of all your options alot and this suited you

Yep, went over this in my mind a few times. There was a time when I did think about tapping into the side light feed for ease - gookah wired his in to the side lights and deleted the originals, which passed an MOT. No lamp error with this kit. But I wanted these to work independently from the other lights, and be always on (or off) - looking at Nickm's AEs on his E89 the other week I decided this was the right way to go.

It's a good point though, this could have been done a lot easier, especially the parking sensor which is a very easy mod wiring into a power supply and then adding a rocket switch in the cabin - while it lacks the OEM look and feel, it could be hidden (within reach) and no one would ever know.

How do the buttons feel compared to the stock ones?

Not quite right - the BMW are soft with a reasonable amount of travel. These have less travel and feel firmer. Couldn't find a BMW style tactile switch - I bought a few but none were right so I used them up practising my soldering / circuit building.

Would be good to have been able to link the parking sensors to the speed sensor so they automatically go on under say 5Mph.

:lol: Tough audience.

 

[left98204]

Again you come up trumps, very brave and executed brilliantly.

I take my hat off to you yet again.

Echo the thoughts of the BMW service guys when they see it :rofl:

 

[easty027]

what a write up !......looks great and you have to have balls to try something like that, so congratulations. i cant believe how the buttons turned out, look great.

 

[pvr]

Fantastic work.

So .. I guess you are never going to have heated seats then

 

[jonnyfive]

Seen this on Sunday in the flesh when we did the reccie 1st class job . Nice one matt

 

[a11y]

Seriously impressive stuff Matt - loving the lego mould :lol:

Someone said it earlier but this stuff you've been doing is seriously ballsy - I like the fact you don't bodge anything, I'm a bit of a perfectionist too

 

[Siftah]

Seriously impressive work Matt, top job