Coding Help? How To Upgrade M73 AGS to M/S-Gate Sport Mode program selection

[m6bigdog]

(Update: Oct. 2022)
So, Now I Know "How To Upgrade M73 AGS to M/S-Gate" and Sport Mode Transmission Control Modules now available:
Instrument Cluster EGS Display image Below
Go To:
https://www.bimmerforums.com/forum/s...DONE-Wonderful
https://www.bimmerforums.com/forum/s...rogram-Finally


.....
Any ideas on how to upgrade/code/program the E31-M73 "GS9.22.1" or other modules in the car so it will have a M/S gate Sport Mode?
Do I need to code or initialize the DME or instrument cluster if I swap the EGS modules?


I think BMW extracted just about all the torque/HP out of these 5.4L-2-valve engines.
I upgraded the diff to a 3.23:1LSD that does wonders for rear wheel torque and traction with only a minor RPM increase.


Currently, the E31-M73 M-Gate Steptronic transmission program "Code: NW" cannot manually select 1st gear.
Also, there is no Sport Mode selection with M-Gate; so the transmission normally shifts from 2nd - 5th gear (however, an aggressive throttle position at start-off will induce the head snapping Kick-Fast program with a 1st gear down-shift at start off)
See attached Adaptive Transmission Control PDF



Personally, I would prefer a Steptronic program with a "Sport Mode" M/S-Gate gear selection update for the E31-M73.
1) Sport M/S-Gate selection for 1st gear and a 1st gear start off.
2) Sport M/S-Gate mode that uses 1st - 4th only. Keep the trans out of 5th on city streets.


The 750-E38-M73 has the Steptronic M/S-Gate.
The AT-EGS control units are both "GS: 9.22.1":
850-E31-M73 "Code: NW" (24 60 1 422 870)
750-E38-M73 "Code: OF" (24 60 1 423 200)
In the BMW parts catalog the 24 60 1 423 200 supersedes the 24 60 1 422 870
That I can see both the E38-M73 and E31-M73 use the same DME units.
I'm aware the GS: 9.22.1 is not programmable in the car but the EPROM are replaceable.

I swapped an E38-M73 EGS "Code: OF" control unit into my E31 but it causes a Trans Program Fault.
I anticipate the EGS-DME hand-shake or CRC fails!!
Next I will try swapping the E38-M73 "Code OF" chip into the E31-M73 EGS control unit to see what happens.


I believe "Firebird540" or "Firebird850" did the DME and EGS upgrades way back when, however he lives in Germany and only did the DME upgrades in person when he came to Las Vegas.
Post:
http://forums.bimmerforums.com/forum...3#post25913483
As for the EGS updates: "I may think about to do a software for 5HP30 tranny only that will be a "remove old original EGS and put my modded EGS on". It will work with the original DMEs and EMLIIIs and later could be used with the modded DMEs and EMLIIIs if someone decides to upgrade later."

I have a lot more official BMW technical information on the Transmission and EGS but with a 1M file size limit most cannot be uploaded

[Auraraptor]

It was odd the E38 got a sport mode on the slightly modified M73TU + 5Hp30 but none of the updates on that car explain why sport mode was disabled for the E31.

GL!! I know I will be following this thread extremely closely. It is also peculiar only the 840 M62 cars got sport mode. I believe they also had 5hp24s, however.

[CD05001CIA]

videos:

[Auraraptor]

Yes but unfortunately no one has been able to replicate his work

[m6bigdog]

Just to closeout my EGS upgrade efforts, accomplishments and final discussions on the E31-M73, GS9.22.1 Transmission Control Module EPROM Update for Sport Drive Mode and Manual mode M1 selection:
See URL Below:


850Ci M73 Steptronic M Gate - Upgrade to M/S Gate - Sport Drive Mode - DONE Wonderful
https://www.bimmerforums.com/forum/s...DONE-Wonderful

[Auraraptor]

Yes wonderful work, thank you again. Now we just need someone to figure out how to use programmable chips!

[m6bigdog]

Yes wonderful work, thank you again. Now we just need someone to figure out how to use programmable chips!

You're welcome!!

The GS9.22.1, TCM doesn't have the internal circuitry to use an EEPROM. Hence the chips need to be swapped no matter what!!
Neither does the DME-M52
IMHO: DME reprogramming is overrated!! Speed Limiter? not interested!!
After that, someone is more likely to upgrade to the DME-M52.1 Flashable in the E31-M73 (same as the 1998 E38-M73N, however the TCM EPROM program would also need to be replaced if the E38 DME program was used.
The E31-M73, M52-DME program certainly would not be compatible with the M52.1 DME
Also, it is questionable if the E38-M73N, M52.1 DME CAN Bus communication routines for the Instrument Cluster, EML, DSC, etc., would be compatible with the of the E31 modules??
IMHO, way too much work. Just upgrade, reprogram and swap the DME-M52 EPROM!!
Then the question is, what would be the real advantage of a flashable DME, as any experimental changes should first be bench tested and not installed/tested in the car where it is possible to destroy the engine; in short order!!!

I will never chip my E31-M73, DME-M52 and risk the engine...The 3.23.1 LSD and SD-TCM is way more performance than any DME upgrade.

[Auraraptor]

For me, tuning to accommodate complete exhaust

[m6bigdog]

For me, tuning to accommodate complete exhaust

Given the cam's short duration (240) and conservative spread angle (I-112) (E-109), I doubt any free-flow modifications to the exhaust system, to including headers would require DME compensation.

[Auraraptor]

It’s not that part I need tuning for….it’s the CEL. I always seem to get one with high flow cats….

[petejk]

It’s not that part I need tuning for….it’s the CEL. I always seem to get one with high flow cats….

Suggest trying a couple of sets of o2 sensor spacers.
I’ve used them with success on a previous car in the past with aftermarket cats


Sent from my iPhone using Tapatalk

[m6bigdog]

It’s not that part I need tuning for….it’s the CEL. I always seem to get one with high flow cats….

Auraraptor,
Please, Is there a thread you can point to? or could you start a new thread, so we can do a DEEP DIVE into the problem.
I want to become informed about M73 possible CAT replacement issues.

A few of my questions?
I anticipate it is the after CAT O2 sensors that are throwing out error, however you didn't say.
What is the error code?
Have you replaced the O2 sensors within 60k miles?
Have you looked at the DME adaption readout?