Black & Tan 332iT

[Bry5on]

Ok, we left off Friday with a bunch of the rear end work done, but we hadn't started on anything forward of the rear seats bench. Yesterday was another productive day and I was able to get PDC fully functioning in the car, button and all. We also got on with a bonus of hardwiring in an AEM CAN-based Wideband O2 sensor, for automatic datalogging with Gauge.s whenever I plug the device into the OBD2 port. No more laptop with Testo and slow datalogging speeds (CAN is roughly 10x the data rate). On to some paraphrased play by play:

Starting with wires routed to their destinations and some coffee, we get to work:


The e46 rear PC harness I bought looks like it was specific for the sedan/coupe and not the touring. I hadn't thought this one through ahead of time and was surprised in the moment that I was about 3' short of running the wires in the factory location behind the rear woofer. Fortunately, I'd grabbed some spare harnesses from an e53 X5 and I took a page out of the X5's book. The X5 has an intermediate harness between the rear PDC sensor harness and the PDC module harness. It uses the same pins as the e46 harness, so I depinned the e46 connector and swapped pins into the mating X5 connector to create an effective extension harness identical to the X5 setup without cutting any wires. Pleased with this workaround.


I'd also been building the harness and routing wires for the trailer module. I started with the X5 trunk harness and ran all the input wires to the bundle right above the battery. I also dropped the two rear fog out wires (run to the LCM pins 20 & 49) and the X5's 12 pin trailer-out plug into the same location, along with 4-pin trailer connector loose wiring, making all future junctions accessible in the same location (tail light harness is right there), as I'm sure there will be debugging to get this all working and I don't want to be tearing into a bunch of interior panels again.


I'll spare you all photos of the wire routing along the sill and up into the fuse/junction box area, but suffice to say it was all routed along factory routing paths, at the usual junctions, grounds, positives, etc. While I was there I added this AEM in-line CAN Wideband O2 and terminated that along the factory harness to a ground block and unused cabrio Fuse 13. It tucks nicely below the general module and the O2 sensor wires pass through the firewall grommet along with the front PDC harness for a clean install.



After the passenger side wiring was complete, I passed a whole bunch of wires behind the AC panel to the driver's side and terminated them in their respective locations, along the factory harnessing:
- Gong power
- Gong PDC signal
- PDC button and light signals
- Rear foglight wires (2x)
- LCM -- AHM comms wire
- AEM CAN comms wires

The result is a fully functional PDC system, front+rear with button and reverse-trigger, a functional gong (I'd already run the wire to the cluster last time I was in there), and AFR now showing on the gauge.s dataloger at 100Hz. I have Gauge.s setup to datalog any time it's powered up, and I wired it to the OBD2 port, along with bringing the car+wideband CAN bus to the OBD2 port. To run a datalog, it's now painfully simple: Plug Gauge.s into my OBD2 port, drive, download to my laptop over WiFi.


At this point, I disabled front PDC and set rear PDC to e46-ish settings with PAsoft


So everything was working great, except the rear PDC was basically always lightly triggering. I used the AVIN's I-bus connection to see which sensors were triggering and it was the side-rears, both of them. Hmm. Well, it turns out that the sensors I stole from the X5 are oriented 90 degrees apart from the e46 sensors. So even though the sensor fits into the e46 bumper strip just fine, it's flipped sideways. This matters because the PDC sensors basically throw a rectangle of signal, wider than it is tall, so if you flip it 90 degrees it will pick up the ground, constantly. Well the e46 sensors are kinda ugly, I've got a whole bunch of modern sensors here, and I've got the plastic punch piece and two self adhesive PDC mounts that I didn't use. So I measured the factory PDC bumper strips and made my own that use the modern sensors. Voila, no false triggering from the ground anymore:


And we're done until 4 more adhesive PDC mounts arrive to do the front:

[Bry5on]

Good progress today, the car currently has lots of loose/bundled wires in prep to be run down the door sill, but the installation of the F10 PDC sensors with F10 adhesive mounts went very well. The mounts are slightly angled both upward and inward which puts them pretty close to level and pointing straight back, accounting for the curvature of the bumper. They look very inconspicuous, unlike the factory ones, and work just as well (I did test after install . Important to note that the newer sensors have Pin1: Ground, Pin2: Signal, and Pin3: Positive Supply. Don't go by wire colors as BMW changed the colors to mean different things across generations, in their infinite wisdom.

All told the combined PDC and trailer retrofit adds under 5 lbs, and I added 1lb of sound deadening to the rear to continue to try to quiet the cabin down on the highway. I can stomach 6lbs, especially in the rear. If I ever feel motivated down the road, I'll have to pull the trunk panels, add deadener to the wheel wells, then replace the sound deadening that someone sadly cut a hole in for strut mount access. I'm running the studs that can be accessed from the wheel well so I'm happy to close that location out.

Back to PDC. I marked the center locations thanks to some help from e46fanatics forum members, then used double stick tape to adhere a makeshift drill bushing to locate the PDC sensors in the factory spot. Then I punched the holes out using an 18mm punch kit. Following that I used the jigsaw to cut some rectangles in the bumper beam similar to what the factory did, then routed a trailer harness through the PDC grommet, tied the harness up to the factory studs with plastic harness ties, adhered the PDC mounts and slapped the bumper back on. I think it turned out pretty great:



Then a quick test with the rest of the bench top setup (works great):



And following that it was time to start the trunk and interior disassembly to run a whole bunch of wires. I'm running a PDC supply harness (for an e39), front PDC harness, making my own trailer harness, terminating at factory fuses, grounds, pins, etc. It's loads of fun, and that's where we are today:

[Bry5on]

Managed to do some multitasking while taking calls this evening - windowed out the rear bumper cover for the corner sensors (using original e46 sensors there for now) with a stepped drill bit and some flush wire cutters. The inner bumper support has a square hole, it's just a matter of matching the square for the sensor to pass through.

The F10 adhesive mounts are angled just slightly upward, so I think they may just work out, hoping they don't point the sensors too far downward and pick up the ground.

And so it begins.

[Bry5on]

Dad happened to have not only the e53 AHM lying around, but found a factory 7-pin hitch harness as well. I snagged the body side AHM harness from an e53 already, so this will simply plug and play.

[Bry5on]

New seat bottom insulation showed up to replace the crumbled bits that came out. Hoping this will reduce some highway noise. Anyone have any experience quieting down a touring? I’m thinking the trunk/subframe/tailgate areas transmit some extra noise and it would be great to cut it down a bit. Those urethane subframe bushings probably don’t help now that I think about it.

[Obioban]

That's some dedication to an unusual task

[Bry5on]

That was more work than I expected. It turns out the sport button gets a GROUND signal from the DME, where the PDC sends a 12V signal. Also the button needed some serious trimming, epoxying, etc on the back side to fit. Thanks heinzboehmer for buying another M3 and letting me pillage it the day after you picked it up!

Regardless, perseverance paid off. It’s ready for the PDC harness

[Bry5on]

Ok, really getting into the weeds with this one. We'll be breaking down the switching center and how it's designed/electrically functions for a non-convertible M3 (and probably some non-M configs).

There are 7 total button positions. Each button on the circuit board has 8 blade connections to the button. The PCB is designed to maximize use of these blade connections, so some of them are bridged on the board to allow some buttons to be placed in multiple locations. This allows for different combinations of options on the car.


Each button works by pulling a momentary ground to some pin. There are three 'types' of button for the center 5 buttons, they differ by which pin they pull to ground when you push them. Either pin 3, 4 or 5. They even have different PCBA part numbers



Via some rather tedious circuit tracing, here's the matrix of blades that are connected (top) and 'what button can go where' (bottom)


You can see that the sport button (or any green LED capable button that's not HK) can only be on pins 4, 5, or 6 and you can't have two different green LED buttons in those positions, because they'll just reflect the state of sport mode. This is a problem for me because I want to add PDC which has a green LED button.

The solution: Modify a DSC button by performing the following:
1) Clean masking off of Green LED pads
2) Populate the Green LED from a donor
3) Cut the trace for the sport light from blade 7
4) Bridge the trace for the sport light to blade 4 (they're RIGHT next to each other. Easy)

Then add a quick white-wire solution to the board (totally reversible! But doesn't need to be reversed ever, anyway):
1) Bridge Position 6, Blade 5 directly to Pin 9 of the switch center plug (button press)
2) Wire 550ohm resistance from Position 6, Blade 4 to Pin 8 of the switch center plug (green status light)

This will allow me to use Pins 8 & 9 just as the e39 and e53 did for the PDC pins, while also making sure any changes I'm making are easily 100% reversible by simply removing my custom button. Because Position 6, Blades 4 and 5 are not used on the board, or for any button function in any e46, I can leave these wires permanently in place with no ill effects.

Next step will be customizing the plastic of the e39 PDC button to fit in the e46 style housing. Stay tuned..

[puma1824]

I used the rallyroad brackets, no machining or grinding required in the rear.

Honestly I'm not sure I'd recommend this setup, it's not really much better or different than stock, really mild increase in pedal feel. If you're running big wheels, just put on the F80 stuff. Those brakes are great (I've only driven them in the F80, FWIW).

Good to know. Yeah I think I'm kicking myself for not pulling the trigger on the F80 kit when my car was being done. Honestly the only reason I didn't do it was because I wanted to keep the unsprung weight down. Additionally I do currently have on hand but not installed the Megane RS Trophy-R Brembo fronts. I think this setup could be but not confirmed lighter than the F80 setup. Maybe i should still keep stock ...damn these cars lol


Sent from my iPhone using Tapatalk

[Bry5on]

Which adapters did you use on the rear 996 calipers? Any machining required on the calipers to make them fit?

I used the rallyroad brackets, no machining or grinding required in the rear.

Honestly I’m not sure I’d recommend this setup, it’s not really much better or different than stock, really mild increase in pedal feel. If you’re running big wheels, just put on the F80 stuff. Those brakes are great (I’ve only driven them in the F80, FWIW).

[puma1824]

Which adapters did you use on the rear 996 calipers? Any machining required on the calipers to make them fit?

[Bry5on]

Okay so there’s no option to use rear fogs as brake or turn signals like I thought in NCS, but there are a couple things that may be related. Going to have to probe around in there, and if there’s no way to do it like the X5, I’ll put a converter box on the inlet side of the trailer module. That’ll keep the detection/PDC disable while guaranteeing the lights work correctly.

The settings in NCS expert that I need to play with (AH and AHM):




While I had NCS expert open, I corrected my FA to include all the retrofits I’ve done:
$464 - ski bag
$508 - park distance control
$521 - rain sensor
$710 - M leather steering wheel
$716 - m-tech 2 aero kit
$760 - high gloss shadowline
$772 - black cube trim
$775 - anthracite headliner
$7MA - M3 competition package (brake bias, m-track, steering rack)

[Bry5on]

And while I'm in there running PDC harnesses, I'll be running the two/four wires necessary for the OEM tow hitch module. Again using one from an e53 because those are intended for US trailers (although I'd bet they're the same internally)

[Bry5on]

Morning update: late style e53 buttons work the same, we’re on.

[Bry5on]

Brake update: very much silent still on the red brakes after 500 miles or so.

Side project update: Looks like Front + Rear PDC retrofit is pretty trivial, got it all working on the bench. I’ll be using f01 black sapphire sensors in the rear bumper in place of the giant factory ones, and flat black/unpainted sensors in the front bumper strip in an attempt to avoid drilling/cutting the bumper support beam. By retrofitting the e39/e53 stuff, that also means my rear PDC beeps will actually come from the rear of the car, instead of under my feet.
Front e39 retrofit harness PN: 61-12-0-027-997
Main/power e39 retrofit harness PN: 61-12-0-027-006
Rear e46 harness PN: 61-11-6-930-771
f01/02 self-adhesive bumper mounts for the f01 sensors: 51-12-2-147-035

Anyone want to donate an M3 switch console that has the roller blind in it? I need the extra button location for the PDC button now. Late model e53 uses the e46 style buttons which should swap right out for the roller blind with a quick white wire job inside the switch center enclosure.

Warning, beeping noises are loud, louder than my voice:

https://youtu.be/qVv13uDgmcE?si=gYfocWP7Plq3Pv2i