850Ci M73 Steptronic M Gate - Upgrade to M/S Gate - Sport Drive Mode - DONE Wonderful

[m6bigdog]

It all depends on your craftmanship. It won't be plug n play as just the trim alone with the M/S +/- slot is a different shape you would have to incorporate into the E34 wood piece.

Folks here don't seem so keen on doing to reversal as you can see from the reactions after my post on page 1.

The E31 Steptronic Manual mode +/- shift reversal was accomplished many year ago and was well published at the time and still easy to look-up, attached DYI instructions.
IMHO, it is just a novel modification that has no relevance for actual performance.
Now, if you happen to have another vehicle with the Tipping reversed from the E31, it may be worth the effort.
Otherwise, why go to the effort to make the vehicle operation different than the factory documentation?

[MParallel]

You just swap two pins over, which can be reversed at will.

Why would you care how it's written down in the documentation? Then this whole topic about changing the gearbox control unit and what not is also changing the factory documentation. What's the difference?

It's nothing to loss sleep over. It's just the natural way to shift. If people think otherwise, that's because they have been conditioned to a unnatural pattern. Which is ok, as it will be just fine for *that* person. Even some hight end sportscar still have the unnatural pattern in use today.

It's the same as right shift paddle is always for upshifting and left for down (in case of separate function per side, those double fuction paddles are just dumb), you'll never find that reversed.

Paddles, btw, which would be a nice additional mod on top. Then it doesn't matter the pattern on the stick side.

[m6bigdog]

May I offer some advice and also ask a question.

The advice is that it is fabulously easy to reverse the direction of the step-tronic lever ...

For both my conversions ...

So now my question. I also have a 1995 E34 Alpina B10 4.6. It has the M60 engine mated to a 5HP30 gearbox but both the engine and the gearbox have been tuned/played with by Alpina. While the gear lever gate is the non-steptronic type...

Attachment 710661

...the switch next to the gear-lever changes the gearbox mode from fully automatic to Switch-Tronic meaning I can change gears manually from the buttons on the back of the steering wheel as shown by the stitched arrows...

Attachment 710662

My question is, given that I have the same (similar) 5HP30 gearbox in the E34 as I have in the E38, and I already have the wiring in the car (the Switch-Tronic from the steering wheel) to make the steptronic gear-selector gate work would it be possible to retrofit an E38 gear-lever so that I gain the ability to use the gear-lever to change mode and also change gear, just like the E38 and E39 do?

Many thanks for any advice.

I assume Alpina added a custom electronics module to adapt the Manual shift selection into the Up/Down Buttons on the Steering wheel.
I anticipate once you select Manual Mode the gear selector 2-4 no longer functions or if you select 2-4 gears Manually (by the shifter) the Steering wheel buttons no longer work?

From there it is all about BMW factory electronics, DME and EGS-TCM compatibility.
As I discussed in another reply. Reverse engineering the TCM, building a DME/Transmission simulator and programming an EPROM with custom values for a one-off upgrade is a hobby only an owner with the electronics knowledge could endure.

From there you could only hope (big question) to find factory developed/production modules that would play together and accomplish your desired Steptronic upgrade.

That I'm aware for any BMW Series:
The M60 DME used the M3.3 version. DME EPROM adapts the Engine Series to the Vehicle Series (chassis weight, etc.).
The M60-M3.3/5HP30 was used with the GS9.20/GS9.22 only. TCM EPROM adapts communication between the DME, Instrument cluster and Gear Shifter.
BMW Training Manual extraction attached...


The M60-M3.3/5HP30-GS9.20/GS9.22 was only offered with the non-Steptronic gear-shifter. (Strike 1)
(corrections)
The M3.3 was interfaced with the EGS GS9.22 TCM however not as a Steptronic (Strike 2)
Can the Steptronic gear-shifter be connected to the GS9.22 used with a M3.3 DME and not Cause a Trans-Fail? (Maybe - Would most likely depend on the DME and AGS software code)
The Steptronic gear-shifter with the EGS GS9.22/GS9.22.1 was only used with the M5.2/M5.2.1 DME's. (Strike 3)

The communications between the DME, IC and EGS is done over the CAN BUS.
The GS9.22/GS9.22.1 will work with the non-Steptronic gear shifter but you want more than that.
Is it possible a GS9.22/GS9.22.1 from an M62-M5.2 DME will work with the M3.3 and E34 Instrument Cluster? Doubtful, The DME, IC & EGS communicate on the BUS at power-up so you would most likely get a Trans-Fail, but that would be the first thing I tried before I installed the Steptronic Gear Shifter.
It is possible the EPROM from the GS9.22 will work in the GS9.22.1 to solve the power-up handshake to get past the Trans-Fail? Maybe? however, the Steptronic function would most likely be lost (not in the GS9.22 EPROM programs) and the gear selector would only work as a non-Steptronic Selector with M/A switch?
Is it possible the Alpina electronics module will work with the Steptronic Gear Shifter? That only you can explore and evaluate for yourself. I doubt Alpina released the schematics for their upgrades to the B10 and you need the schematics or a module to reverse engineer the circuits or you risk damaging the EGS and Alpina module.

You may have all you can get and that is not bad compared to the Stock E34

Have Fun...

[m6bigdog]

You just swap two pins over, which can be reversed at will.
Why would you care how it's written down in the documentation? Then this whole topic about changing the gearbox control unit and what not is also changing the factory documentation. What's the difference?
It's nothing to loss sleep over. It's just the natural way to shift. If people think otherwise, that's because they have been conditioned to a unnatural pattern. Which is ok, as it will be just fine for *that* person. Even some hight end sportscar still have the unnatural pattern in use today.
It's the same as right shift paddle is always for upshifting and left for down (in case of separate function per side, those double fuction paddles are just dumb), you'll never find that reversed.
Paddles, btw, which would be a nice additional mod on top. Then it doesn't matter the pattern on the stick side.

WOW!!!
IMHO, you should start a thread on the topic to see who else cares.

[E36Ron]

The main thrust of this thread is the driveability value-add of being able to invoke the BMW S-Program by a simple left move of the shift lever in the 363 examples of the M73 E31 850 automatic. Those value-adds include always available access to first gear, and much sharper performance in automatic mode in "spirited" part throttle driving.

But all of this discussion of more complex electrical mods prompts me to suggest that the REALLY most valuable such mod would be to be able to bring out to the instrument cluster the ACTUAL gear in which the car is running at any given moment. A tell-tale light indicating when the torque converter lockup clutch is engaged would also be a nice little extra.

Right now, there seems to be no bullet-proof way to determine when (if ever) the D-program engages first gear at less than a full-throttle takeoff.

The 5HP30 transmission is so smooth at light loads that the only way I have found to reliably test this difference between D-mode and S-mode is to count gearshifts from a part throttle standing start all the way up to 80 MPH, where I know for sure that in 5th gear with TCC engaged and a 2.81 axle the engine RPM is just a shade over 2,000 RPM.

This requires a long, straight, flat, EMPTY stretch of highway or back road, and then you have to watch out to include TCC engagement in the shift count. When I find the right environment for such a test, I will report back.

Meanwhile, another useful trick would be for someone to create a test rig that plugs into the OBD II port, and outputs the currently operative gear and TC clutch status. That too would be fun!

-- E36Ron

[MParallel]

WOW!!!
IMHO, you should start a thread on the topic to see who else cares.

Maybe I will. Thanks for the tip.

[m6bigdog]

... Those value-adds include always available access to first gear, and much sharper performance in automatic mode in "spirited" part throttle driving.
But all of this discussion of more complex electrical mods prompts me to suggest that the REALLY most valuable such mod would be to be able to bring out to the instrument cluster the ACTUAL gear in which the car is running at any given moment. A tell-tale light indicating when the torque converter lockup clutch is engaged would also be a nice little extra.
Right now, there seems to be no bullet-proof way to determine when (if ever) the D-program engages first gear at less than a full-throttle takeoff.
The 5HP30 transmission is so smooth at light loads that the only way I have found to reliably test this difference between D-mode and S-mode is to count gearshifts from a part throttle standing start all the way up to 80 MPH, where I know for sure that in 5th gear with TCC engaged and a 2.81 axle the engine RPM is just a shade over 2,000 RPM.
This requires a long, straight, flat, EMPTY stretch of highway or back road, and then you have to watch out to include TCC engagement in the shift count. When I find the right environment for such a test, I will report back.
Meanwhile, another useful trick would be for someone to create a test rig that plugs into the OBD II port, and outputs the currently operative gear and TC clutch status. That too would be fun!
-- E36Ron

Ron,
Yep the TCM and 5HP30 are technically complicated!!
The AGS Programs are complicated to say the least;
With exploration of the various documented function and seat-time you can both control and anticipate the gear-changes.

I have yet to find where the automatic gear selection in SD or D-Position is ever communicated from the TCM on the CAN Bus. If the automatic gear selection is not on the CAN Bus it can't be available on the OBDII or DIS ports.
Building a test jig is doable, however it is complicated by the variability of the signal levels sent to the 3 each solenoid and 5 each pressure regulator valves.
So the 8 valve control signals would need to be conditioned into a 0/1 logic level with schmitt triggers then the logic of the power flow would need to coded into the Selected Gear lamp driver.
FWIW, Torque Converter Lockup is applied by Pressure Regulator valve #4 column, -X- in D4 and D5 row.
Attached: A5S560Z Power Flow and GS9.22.1 block diagram.

We must ask the question, what value is knowing what gear has been selected automatically when in SD or D-Position.
In SD & D-Position, you can apply what ever throttle your heart desires and the TCM will select the appropriate gear based on rate of throttle application, RPMs and the SD or D-Position program.
Also, for the gear selected display to be of value, you would need to look at the display and the engine RPMs at times of critical maneuvers or cornering for it to be of real driving performance value.
I suggest during critical driving situation, when the gear selection is critical, tapping into Manual mode then the gear selection is controlled by the driver/gear selector, with up-shifts at the RPM limit and not the whims of the SD or D-Position automatic gear-change programs.

As for 1st gear in D-Position: Definitely never at take-off only after down-shift!!
1) Kick-down switch will cause a down shift into 1st gear. (Hang on)
2) Kick-Fast will cause a down shift into 1st gear. (inconsistent application)
3) best to use SD for the initial 1st gear take-off, then transfer into D-Position once the SD Programs is not desired. (consistent - no fuss real deal 1st gear take-off)

The difference in D-Position 1st gear Take-off:
Kick-Fast is a rate of throttle depression and has nothing to do with WOT Kick-Down switch.
Before the SD-TCM, I used Kick-Fast to engage 1st gear Take-offs with a fast tap of the throttle. The tap is a quick throttle application and release to cause the Kick-Fast down shift, however the issues are: the down-shift delay and how much throttle remains after the throttle release?
The throttle application part of a Kick-Fast Take-off is inconsistent so the Take-Off can be excessive.

Gear-Change evaluation:
I suggest you study the RPM/MPH/Gear chart you made.
Note, between 2k-3k RPM the MPH has very little overlap between gears.
Watching for the RPM drop is best method to detect the gear change and using the speed @ gear-change to determine which gear change occured.
I.e., for my 3.23:1 final drive chart:
Gear change @ 13-19 MPH under 3K RPM that is a 1-2 gear change
Gear change @ 20-30 MPH under 3k RPM that is a 2-3 gear change
and so on...
With a little practice who needs gear lights..

As I said:
My routine is, take-offs are in SD! just hang on and drive (no need to count gears)...maybe a tip +/- to activate Manual mode, then into D-Position (5th), back into SD for slower speeds and take-offs,....on-and-on...

Really Having Fun Now...

[m6bigdog]

You just swap two pins over, which can be reversed at will.
Why would you care how it's written down in the documentation? Then this whole topic about changing the gearbox control unit and what not is also changing the factory documentation. What's the difference?
It's nothing to loss sleep over. It's just the natural way to shift. If people think otherwise, that's because they have been conditioned to a unnatural pattern. Which is ok, as it will be just fine for *that* person. Even some hight end sportscar still have the unnatural pattern in use today.
It's the same as right shift paddle is always for upshifting and left for down (in case of separate function per side, those double fuction paddles are just dumb), you'll never find that reversed.
Paddles, btw, which would be a nice additional mod on top. Then it doesn't matter the pattern on the stick side.

850-M73 Steptronic M/S pattern with Manual mode +/- swap.
Here you go, all done!!
https://www.bimmerforums.com/forum/s...2#post30851782

[Auraraptor]

850-M73 Steptronic M/S pattern with Manual mode +/- swap.
Here you go, all done!!
https://www.bimmerforums.com/forum/s...2#post30851782

Looks wonderfully factory!

PS did you remove all your wood trim? Neat HiFI button...I never saw that in an E31 before.

[m6bigdog]

Looks wonderfully factory!
PS did you remove all your wood trim? Neat HiFI button...I never saw that in an E31 before.

The console wood trim Birdseye Maple was cracking when I purchased my 8 in 2004, so I decided I wanted something that didn't look damaged.
When I purchased all the console parts in Black it also afforded the opportunity to add the electric rear shade and E36 Harmon Kardon Top-HiFi DSP sound system button to the console.
The 1999 E36 Harmon Kardon TOP HiFi DSP sound system uses the same harness wiring as the E31 HiFi 10 channel system and I added the Sound switch wiring harness to the amp and swapped all the woofer & mid-range speakers to the 2 ohm versions.
Since the CD-43 head unit uses the I-Bus CD-Changer, I installed the I-Bus Data Cable and 1998 E38, I -Bus CD-Changer, same form-factor as the original M-Bus E31 CD-Changer, only the E38 CD-Changer never skips - never!!
All is much better than anything that was factory in the E31, to include the all CD conversion.

[TedBobo]

The console wood trim Birdseye Maple was cracking when I purchased my 8 in 2004, so I decided I wanted something that didn't look damaged.
When I purchased all the console parts in Black it also afforded the opportunity to add the electric rear shade and E36 Harmon Kardon Top-HiFi DSP sound system button to the console.
The 1999 E36 Harmon Kardon TOP HiFi DSP sound system uses the same harness wiring as the E31 HiFi 10 channel system and I added the Sound switch wiring harness to the amp and swapped all the woofer & mid-range speakers to the 2 ohm versions.
Since the CD-43 head unit uses the I-Bus CD-Changer, I installed the I-Bus Data Cable and 1998 E38, I -Bus CD-Changer, same form-factor as the original M-Bus E31 CD-Changer, only the E38 CD-Changer never skips - never!!
All is much better then anything that was factory in the E31, to include the all CD conversion.

Wow!

[MParallel]

850-M73 Steptronic M/S pattern with Manual mode +/- swap.
Here you go, all done!!
https://www.bimmerforums.com/forum/s...2#post30851782

And all the time you were so against the reversal of the manual pattern.

What happened?

[m6bigdog]

And all the time you were so against the reversal of the manual pattern.

What happened?

Not against +/- reversal.
Against HACK jobs.
What you see is, where form meets function; shift indicator matched the shifter function..
That I'm aware this is a FIRST;
850-M73 with SD TCM and reversed +/- on the console shift indicator!!.
A week ago, I had never seen this done!!

I wanted to replace the 850 Manual mode console shift pattern to match the SD TCM upgrade, but I had yet to workout the details.
With the help of others, I could choose the M/S upgrade only or M/S with a reversed +/- manual mode.
How cool is that!!

I decided the M/S and +/- reversal would be the best example of what is possible, more than an itch I needed to scratch.
It will take some getting use to, we shall see if I keep it reversed!!
I can easily replace the shift pattern with a non-reversed version and swap the pins back in the connector.
But now, the example is still there for others..
That is; "What happened?"..

[MParallel]

Fair enough, but just swapping the pins, which is all there is to it, I wouldn't call that a heck or HECK job, when the pattern on the shifter is still the original.
I doubt many people even look at it during shifting. Of course having it matched, is nicer no doubt.

I was just surprised this was even an option, seeing one particular post. Anyways, you'll quickly get used to this natural pattern and will wonder how you ever lived with the old. I'm not kidding, but it needs time and time will tell.

Now for the next best mode: shift paddles.

[E36Ron]

As previously noted, what's natural depends upon context.

The stock pattern of up for Up and down for Down is the most natural thing in the world for me.

But now we have clean, elegant solutions for whichever is the most natural to you. Bravo, m6bigdog!

-- E36Ron

[MParallel]

Well what is more natural is of course personal, but it's also what you are used to, and that's what makes it more natural to you. And all is fine of course. There is no 'mandatory' pattern, obviously.

But just to repeat why the pulling for upshifting and pushing for downshifting makes more sense (as used in every real sequential race tranny) is because it follows the vector of force, making shifting easier. When you floor the throttle, to increase speed, you are pushed back into the seat. Hence the pulling for upshifting. And vice versa for slamming the brakes.

The reverse pattern is going full against the vector of force.

It amases me that even some high end sportscars, still use the reverse pattern.

[m6bigdog]

Well what is more natural is of course personal, but it's also what you are used to, and that's what makes it more natural to you. And all is fine of course. There is no 'mandatory' pattern, obviously.
But just to repeat why the pulling for upshifting and pushing for downshifting makes more sense (as used in every real sequential race tranny) is because it follows the vector of force, making shifting easier.
When you floor the throttle, to increase speed, you are pushed back into the seat. Hence the pulling for upshifting. And vice versa for slamming the brakes.
The reverse pattern is going full against the vector of force.
It amases me that even some high end sportscars, still use the reverse pattern.

That is 6-7 replays with your passionate opinion of reversing the Manual mode shift direction.

I would think it has been addressed with detailed discussion and implementation with actual shift indicator hardware available.

Others including myself are educated and think differently than you;
That is,
an E31 is not a race car,
does not have a SMT,
there no real need to grip the shifter,
BMW used the early Manual mode shift direction, why change it,
and yes, many like it that way!!
Now for those that have other vehicles in the stable with the reversed manual shift pattern, it would be good to have consistency and the motivation is obvious. I'll be waiting for Timm to wade in on this one!!

In the USA we have the term "Beating a Dead Horse".
I think we are there!!!

[CD05001CIA]

I've spent years pushing forward to shift up ? ? ?


and pulling back to shift down . . .


(when, IF EVER, I used the manual mode)


Deadhorse.jpg

[kombinator]

Hi, Quick question.

I have seen in the documentation two different look-up-tables for gear indication in the cluster. one is for 4hp and the other for 5hp, or even steptronic?
One goes PRND123 (4hp)
The other PRND234 (?)

What does your cluster show? M1 M2 M3 M4 M5 or only M2 M3 M4 D ?
I have different versions of EKM and Cluster, but can only make it show 123 as a number other than that is stays blank. The Lines L1-L4 are logic lines that should allow 16 different combinations. More confusing is that the logic for PRND is not the same for both setups...

okay I have found some info in this thread:
https://www.bimmerforums.com/forum/s...nd-EGS-Modules

[m6bigdog]

Hi, Quick question.

I have seen in the documentation two different look-up-tables for gear indication in the cluster. one is for 4hp and the other for 5hp, or even steptronic?
One goes PRND123 (4hp)
The other PRND234 (?)

What does your cluster show? M1 M2 M3 M4 M5 or only M2 M3 M4 D ?
I have different versions of EKM and Cluster, but can only make it show 123 as a number other than that is stays blank. The Lines L1-L4 are logic lines that should allow 16 different combinations. More confusing is that the logic for PRND is not the same for both setups...

okay I have found some info in this thread:
https://www.bimmerforums.com/forum/s...nd-EGS-Modules

The shifter switches in the referenced schematics is only part of the IC EGS Display as the displayed gear selection characters are a combination of the shifter type, shifter position, inputs into the EGS and the AGS program running in the EGS.
Of course the M70-4HP is a 4-speed and the M60/M62/M73-5HP are all 5-speed.
The steptronic is an adaption of the shifter configuration (PRND with tilt +/-) that the EGS's AGS program interpretes to control the 5HP transmission gear selection.
The M70-4HP & M60-5HP never used the Steptronic shifter and the M62 & M73 only used the Steptronic gear shifter.
However, the 5HP TCM and AGS program is dependent on the gear shifter and engine type so there are numerous AGS program used in the same E31 EGS/TCM.
This post and SD TCM is specifically about the M73-5HP and the Manual Mode Steptronic shifter.

[Rich8]

Hi Rod, just a quick update.
As you know, I have a 1997 850Ci and I got your SD 2.81 GCU

I now have about 600 miles (yes I know it's not much) on this new (to me) GCU and I really am liking it. The shifting is pretty smooth up and down, and I love that it starts off in 1^st gear, and also love that it doesn't shift up to 5^th, unless requested.
So overall, I love the way it all operates now, and I don't see any down side. The car acts just like before, but when I push it, it's a lot more fun.
Well worth the investment, as far as I'm concerned.

In 2021, I helped my friend, Brian here in Phoenix, when we converted his '92 850 from auto to manual, and it transformed his car.....BIG improvement. The auto box in my '97 car was already better than his older type, so I was a little hesitant to make mine a manual. Now I have your GCU, mine has stepped up again; not quite like the manual, but it is a little more convenient in some other ways. My next step is to add paddle shifters.
I'm glad I did this.

[kombinator]

Does the IC EGS display show M1-M5 on manual mode?
All EKM do interpret 6 data lines and send then the display data to the IC. To my knowledge no EKM has a data line input from EGS/AGS.
The EKM works like this:
2 lines aka 2 bit to determine the first digit: 'blank' S M or 'astrix'.
4 lines aka 4 bit to determine the second digit: PRND123 (on 4 gear). Now what you guys with original E31 untouched can tell me, if it is possible to show PRND12345 (that is the question). As explication I have never sat in a working E31 with original drive train and gearbox.
If yes I can continue my trip to decode the data line from EKM to IC.

But you are correct, I will move the text to the other thread that is about EGS display

[m6bigdog]

FWIW,
8 Sport Drive TCM's installed. A few owner feedback replies in this post.
A few SD-TCM's are still available, I have a few TCM's that need to be upgraded and once that is done, I will put my 8 back together soon.
So, when I sell out the current batch of GS9.22.1 TCM's upgraded to SD, it will be awhile before I upgrade more!!

[Auraraptor]

To Echo, above as an independent party, every m73 should have this!!

In a shameless plug, I will also pay top dollar for a bloody steptronic shiftboot with no broken tabs!

[m6bigdog]

To Echo, above as an independent party, every m73 should have this!!
In a shameless plug, I will also pay top dollar for a bloody steptronic shiftboot with no broken tabs!

Rare as hens teeth, forsure.
For months I've searched eBay worldwide, for an original console trim and nothing since last August.

Next opportunity is a Reproduction!
https://octoclassic.com/product/bmw-...iABEgJX5PD_BwE

If you need the boot ring they could make one.
Also, sent an image of the broken bits, maybe there is an easy repair?