[Terry @ BMS]

Hey guys,

Did a local JB4 harness upgrade this weekend and took a few photos in the process to make our DIY. It's a pretty easy process but you will need to follow the directions.

When you get the JB4 upgrade you'll get the new control box and a new power wire. Basically you'll be inserting the new power wire in the DB25 connector and relocating three wire pairs to new positions. What used to be IAT, RPM, and 5v are relocated to CAN+, CAN-, and chassis ground. Numbering is read from the female side of the connector only and the corresponding male pin will always go directly above the female pin. e.g. do not cross up the brown and white wire looms. It should look just like the photo below.

The most common mistake is mixing up the brown and white wires. All numbers are from the FEMALE side only. The male pin always goes directly ABOVE the corresponding female pin. Please study the photo of the gray subconnector below carefully. The photo leaves no room for confusion so any problems you email in regarding the gray subconnector will only be met with ridicule if you do not study the photo.

The last photo shows you where the new power wire goes in the car when installing the harness. More details directions for the power wire install here: http://www.n54tech.com/forums/showthread.php?t=10880

For Pin Out Customers: Instead of relocating the three pairs within the PnP harness you will simply install those three wires in new locations. You should disconnect and reziptie the four new bundles together to avoid install confusion. You will also insert and install the power wire as shown below. This might also be a good time to upgrade to a full PNP harness.


Large black subconnector:
yellow: slot 10 (boost, yellow wire)
black: slot 32 (ground, red/black wire)

White subconnector:
purple: slot 7 (boost solenoid 1, white/gray wire)
green: slot 14 (boost solenoid 2, white wire)
gray: slot 9 (fuel pressure, yellow/red wire, connect on all models)
Red loom previously from large black connector: slot 17

Small black subconnector:
orange: slot 6 (oxygen sensor 1, yellow/white wire with 525 stamped on insulation)
blue: slot 7 (oxygen sensor 2, yellow/white wire)

Grey subconnector:
dark red: slot 7 (throttle position, yellow/white wire. May be blue/white on 535)
White loom previously from large black subconnector: slot 14
Brown loom previously from large black subconnector: slot 1

[Misturrtinnie]

I hope you'll have a couple of these harnesses ready so I can just send in my full JB3 for the exchange. Knowing myself I would mess this up bad. And of course willing to pay a bit extra. Looks like the G4 is gonna be coming out real soon. Good work Terry!

[Terry @ BMS]

We may offer a service to modify your harness for a few dollars if you want to send it in. But haven't really thought about it yet. Since the harnesses get a varying amount of wear and tear depending on how their owners treat them we would not be able to do any kind of exchange program. It would need to be modifying your specific harness.

[lawwailok]

hm...... it looks a bit more complicate than i could manage (according to the pic), a DIY video like the JB3 install would be very helpful. so terry, does it mean we may see the G4 very soon?

[e90AW335I]

T...I can help in my area with this if need be as well. FYI...

[bmwfan19]

i hope g4 install will be same as jb3

[alpinedevil335]

What about for those with pin-outs?

[Terry @ BMS]

Pin outs have it pretty easy. You just insert the power wire in the DB25 and relocate three of the wires on the large black subconnector to new homes.

[temperamental]

Looks easy to me. Now when is the upgrade shipping?

[LostMarine]

Originally Posted by lawwailok

hm...... it looks a bit more complicate than i could manage (according to the pic), a DIY video like the JB3 install would be very helpful. so terry, does it mean we may see the G4 very soon?

at first glance i would agree, but at the same time, the pin-out option looked complicated as well and its really not. im assuming a decent 20 minutes taking your time is all this would need. when i get one ill try it out and report back

[JHOOPS2]

Tools needed?

[Terry @ BMS]

Just the screwdriver shown.

[Terry @ BMS]

Originally Posted by LostMarine

at first glance i would agree, but at the same time, the pin-out option looked complicated as well and its really not. im assuming a decent 20 minutes taking your time is all this would need. when i get one ill try it out and report back

Soon!

[lawwailok]

Originally Posted by Terry @ BMS

Soon!

how soon Terry? please give us a hint

[Terry @ BMS]

Originally Posted by lawwailok

how soon Terry? please give us a hint

From another thread.

Originally Posted by Terry @ BMS

If I had an exact date I'd give it. But hope to have alpha well expanded by Thanksgiving. We have a few more touches to put on the alpha firmware and supplies to build the first 100 "production" versions on the way.

On the bad side I'll be at SEMA this week so it's a week lost.

[JHOOPS2]

Thanks!

[lawwailok]

thanks T =)

[az335iat]

For those with the three port expansion connector (was map selector switch at one time) the correct wire for the power wiring on that connector is the center wire (yellow wire on my three port expansion connector).

[themyst]

heh I should do a harness upgrade service like I did for 18ohm upgrades.

[bwen]

Two quick ones for Terry- will u offer a preorder discount for the G4 and has it been tested on the 335is (not 335i's)?

[Terry @ BMS]

No discounts and we hope to have it tested on the 335is before release. Haven't yet though.

[Fernflex]

Originally Posted by Terry @ BMS

We may offer a service to modify your harness for a few dollars if you want to send it in. But haven't really thought about it yet. Since the harnesses get a varying amount of wear and tear depending on how their owners treat them we would not be able to do any kind of exchange program. It would need to be modifying your specific harness.

I have my Jb3 out of the car, can I send you the harness this week and you send it with the G4 when both ready?

The downpipe fix is no longer need it, right?

[shoes]

At a glance it looks a little daunting, but if you actually read it, it doesn't sound very hard at all.

Out of curiosity, where/what will the new red power wire connect to?

[Darkcyd335xi]

Originally Posted by Fernflex

I have my Jb3 out of the car, can I send you the harness this week and you send it with the G4 when both ready?

T, this ^.... except I'll have mine out for a dealer visit in the next week or two. Any chance this is possible?

[Fernflex]

Ok im crazy and bored I Just changed the cables and took me like 5 minutes!!!

G4 Ready