E38/E39 Cruise Control and Multifunction Steering Wheel Retrofit to a '96 E36
I began by just wanting a new steering wheel for my car, as the one fitted was hideously worn and the leather was ripped, and it spiralled into a complete retrofit of E38/39 GR2 cruise control (I had no cruise fitted), an IBus nav radio and the aforementioned E38 MFL steering wheel. As these things do
But first - a disclaimer. My car is a Euro 03/96 320i six pot - essentially exactly the same as all six pot cars from that age, and this write-up can only be treated as accurate for those type of vehicles. Your four pot or diesel E36 may differ in some important areas, or it may not. I honestly don't know, as it was a hell of a lot of work just to research this retrofit, never mind taking in all the variants of the E36. Your experience may vary from mine, as they say.
All dates used are, to the best of my knowledge, production dates at BMW, not necessarily the year of the registration of the vehicle. Any part numbers quoted are Euro variants, though they may be World Wide - I didn't investigate that aspect. If in doubt, consult a dealer for info, and research through Real OEM.
First - Some History
E38/39 Multifunction Steering Wheels
From 12/95 to 09/96 the steering wheel controls connected to a separate control unit mounted under the dash via 3 wires, which sent out the IBus data on one wire and the cruise control data on another.
From 09/96 to 03/99 (end of production of the type of steering wheel and slipring that will fit an E36) all the electronics were moved into the button housings on the wheel itself, having IBus and cruise data outputs directly, with two slight variants.
1) From 09/96 to 09/97, the steeing wheel button for "cruise off" was marked with an "O" only, it was used with a separate "cruise on" switch on the dashboard.
2) From 09/97 to 03/99, the steering wheel button for "cruise on/off" was marked "I/O" and the separate "cruise on" switch was deleted.
I would recommend getting an MFL steering wheel from any production date fom 09/96 to 03/99, as they are much neater (having no separate decoder box) and because the good news is the code sent by the "O" button on the earlier 09/96-09/97 wheel to the GR2 brain is identical to the code sent by the "I/O" button on the later 09/97-03/99 wheel, the only difference being the printing on the button itself.
I have a MFL steering wheel from a 03/97 E38, and a GR2 brain from a 05/98 E39 fitted to my car, and it works perfectly.
GR2 Control Box (brain)
I only considered GR2 boxes made from 09/96 onward, to more closely match the MFL steering wheel I'd already purchased, so I have no information about the earlier brains. They may be similar, I just don't know.
From 09/96 on, they differ in two important ways (to this guide).
1) From 09/96 to 09/97 the brain used a separate "cruise on" switch on the dashboard. If you get one of these, you will need to source the "cruise on" switch too.
2) From 09/97 to 03/99 the separate "cruise on" switch was deleted, and all operations are controlled by the MFL steering wheel.
I would recommend getting a GR2 brain from 09/97 to 03/99, as again it's neater, not requiring the separate "cruise on" switch. The part number for the brain I got was 8 375 497.
But don't let that fool you, it's the same part number for pre - 09/97 brains as for post - 09/97 ones, it's the internal software that differs. The production date is the important thing.
Cruise Control Actuator/Motor
I think there were two different types fitted to the E38/39 between 12/95 and 03/99 - the earlier type had a round 7-pin connector, and the later type had an oval 7-pin connector. I didn't research the earlier type of actuator, as again I wanted one that more closely matched the ages of the items I had bought, to be safer.
The part number for the actuator I bought is 8 369 027.
I think the type changed on 03/96, but again, I'm not really sure.
I would recommend getting a later one with the oval type connector. Why? Because I know they definitely work
Try to buy a complete actuator, that includes the cable and the fittings at the end. The throttle body on my car came with dual-cams for both the throttle cable and the cruise actuator, and it fitted straight on.
The Wiring Diagram
Right - to the bones of the retrofit. Here is the wiring diagram I came up with. I have marked some connections with a
* then a
number. My notes will follow.
Notes
*1 Power supply.
This is the wire that runs from the engine fuse box, from F46, to the brake light switch at the brake pedal. It is a violet/yellow wire. I picked up the feed underneath the fuse box, but you could just as easily get the feed from the brake switch itself. Those guys with check-control and a 4-wire brake light switch - I'm pretty sure the colours are the same for the wire feeds you need, but please check wiring diagrams.
*2 Gear select input.
This only applies to cars with an auto box obviously, and I don't know if the autobox control unit (EGS) fitted to the E36 even has this output you could use - you will have to research this for yourself. All I know for sure is if you leave this connection open-circuit, the cruise brain will be enabled. I have a manual gearbox, and that's what I did.
*3 Cruise standby light.
To my knowledge, there was never a light in the instrument cluster to show the cruise is enabled on those E36s fitted with cruise as standard, but there was on the E38/39s, so I had to use it
I don't have Check Control fitted to my car, so I wired the output of the GR2 brain to pin 26 of the blue instrument cluster connector, X17. The Check Control idiot light now serves as my "cruise control enabled" light. Not perfect, I know, but good enough, until I think of something better
There are other options depending on what was fitted as standard to your car (in other words, which lights are not used) but be aware - not all of the unused ones can be used for this purpose. The light must have a direct output from the instrument cluster via one of the white x16 or blue x17 connector pins. Please consult the Bentley manual electrical diagram ELE-165 for further info. Some lights show a diode symbol in series with the connecting line - this is fine, as the bulbs in the instrument cluster have a common internal +12v supply, and the bulb is switched on by grounding the output pin. This seems to be how almost all of the lights are lit in the cluster, and works just fine with the GR2 brain.
*4 Clutch switch.
I haven't fitted one of these yet, but I will do, and recommend you do too. I have just grounded this line for the moment.
It isn't as dangerous as it may sound, as the GR2 brain has a rev signal input as a fail-safe, and constantly compares the rate of change of this signal to the rate of change of the speed signal it gets. If there is an obvious difference between the rates of change of these two signals (for instance, if you stamp on the clutch without hitting the brake) it cancels the cruise mode within 0.5 seconds. This equates to a rev rise of about 500 RPM only, so not really a problem.
It has annoyed me on a few occasions though, so it's best to fit one. I will be.
Obviously, those of you with auto boxes need not worry about this - just connect this line to ground permanently.
*5 "Cruise on" Dashboard switch
If you have a GR2 brain manufactured between 09/96 and 09/97, you will need one of these. It is a non-latching press switch that mometarily connects pin 22 of the GR2 brain to ground, to switch the cruise system into standby (ready) mode.
If you manage to find a GR2 brain from 09/97 or later, just leave this pin unconnected.
*6 Cruise Control Data Input
This line connects to pin 4 of the output connector of the slip ring of the MFL steering wheel.
What I don't know is anything about the earlier MFL steering wheels with the separate output box (12/95 - 09/96). This control box also has a cruise output line (pin 5 of X10171). Will this control the later GR2 brains? No idea.
But since it makes little sense to change control data protocols (even if you change the electronics that generate them) then it is a gamble. Your choice, I guess
*7 GR2 data line to EGS auto gearbox
This took me a good while to work out. I'm pretty sure this line sends data to the auto box to tell it the cruise is enabled. As far as I can gather, it's to stop the EGS autobox brain from making annoying upchanges/downchanges when the cruise system is operating.
This definitely applies to the EGS system in the E38/39, and I'm pretty sure it tells the EGS brain to load a different shift programme (like sport, winter etc) but one taliored for the cruise mode.
I have no idea whether anything like this is available in the EGS system of the E36, I just left it open circuit as I have a manual gearbox.
And I think that's about all I have. It was a big project, but very much worth doing.
Hope it's helpful.
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