GM GA6L45R Transmission Relearn Procedure

[jnagel]

UPDATE - 06.2022 - Finally found original TSB with all GM GA6L45R adaptation procedures. Please see my post here for links/info
- https://www.e90post.com/forums/showp...44&postcount=7

Apologies for the long post below, but thought it wise to explain the whole story:

My 2007 LCI E87 130i wth GM GA6L45R transmission was appearing to be shifting between gears (P/R/N/D) roughly lately. Hence, I plugged in my scan tool and I noticed that there was a 578E fault present, the description of which noted that the transmission oil lifetime had been exceeded. At this point, the vehicle had approximately 140,000km and the status of the oil life was at 9% remaining.

A transmission service was carried out some 25,000km ago, and I guess the transmission oil life counter was not reset at this time (which appears to be a common thing left not reset on other forum posts).

Anyway, I then proceeded to reset the counter, after which the oil life returned to 100%.

The next steps I regret performing. After reading online that others performed a transmission adaptations reset after a transmission service/oil lifetime counter reset (an 'optional' task), I explored the process to performing such.

I found a video posted on YouTube which showed how to reset both engine and transmission adaptations. For 'good measure', I performed the engine adaptations component. All went well for that component. Unfortunately, I could not find the same job as depicted in the video to perform the transmission adaptations reset. Due to such, I turned to google to look at why this was different for my vehicle vs the vehicle depicted in the video (an E60). It turns out this was because the video depicted had a ZF transmission whereas I had a GM.

Anyway, after researching potential methods to reset the GM variant, I found a method which involved turning the ignition on, depressing the accelerator all the way down and holding for 30secs, releasing, turning vehicle off and back on. From further research, this appears to be resetting driver adaptations (although there have been mixed results with success from this method) and not the actual transmission adaptations (clutch pressure, solenoids etc).

Anyway, I performed the pedal method as per the instructions. I then decided to look for how to rest the actual transmission adaptations for the GM.

As mentioned, unlike the ZF 6 speed transmission which has this job directly under the 'Service Functions' tab in ISTA, the GM transmission control units (GS1912) does not display a reset job under this tab.

Hence, I found some posts which said that tool32 had the applicable job/s. I opened up tool32, GS1912 control unit, and found the following jobs:
1) STEUERN_ADAPTS_RESET_PLANTS
2) STEUERN_ADAPTS_RESET_WITHOUT_TCC
3) STEUERN_TCC_ADAPTS_RESET

NOTE - nunber 2 and 3 above are also available in ISTA under EGS ecu functions.

I performed all 3 relevant options in tool32 in case one of them did not work (as was also noted on a forum post).

Straightaway when driving, it was clear that something had been affected. Whilst the transmission was much smoother shifting through gears using the selector lever (initial problem) there was also a noticeable rpm flare from 2-3 gear and considerable delayed downshift and 'clunk' when downshifting from 3-2 gear (much like in a manual when the driver does not rev match). All other shifts appeared normal apart from being very slightly slower to change gear when compared with the transmission characteristics prior to doing any fault clearing etc.

After researching again, it was apparent that the shifting problems I was having were due to the fact that the transmission had not been 'relearnt' after the reset. Hence, I tried to find the relearn procedure.

Whilst this is easily available for the ZF, I have still, to this day, not found any solid relearn procedure for the GM.

The only applicable sources were:
1) Sonnax, which detailed a generic procedure for GM transmission after replacing hard transmission components (such as the valve body) and performing a reset (see pic attached)
2) the procedure detailed here - https://forwardassistmechanics.wordp...arn-procedure/ labelled 'Fast Relearn'. (I have not been able to attempt this procedure as ISTA/Tool32 or my scan tool does not have a job with a label as such (unless the aforementioned jobs perform the same thing?)

Anyway, I attempted to perform the procedure outlined by Sonnax. I found a two lane road (had slight decline on way down and slight incline on way back) with 80km/h speed limit (enough to get up to 6th gear etc).

After a good 40minutes of following the procure to a T, I attempted to manually downshift from 3-2gear to see if the clunk had disappeared. To my surprise, it had, and the upshift flare from 2-3 gear had almost gone. I then drove home and decided to re-evaluate it after a week of driving.

Come the end of the week, I was decently happy with the transmission characteristics. However, there were a couple of outstanding issues (such as small upshift flare on cold engine and still delayed shifting from gear to gear) which the the transmission did not exhibit prior to any resets.

Hence, I decided that due to some small mistakes made during the initial relearn (which I thought may have contributed to this),I decided to perform a second reset/relearn to see if I could iron out the kinks remaining.

When ready to do the reset, I went back into tool32 as done before. To my surprise, none of the three jobs I saw before were available. I then decided to go back into ISTA to see if they were available there. Thankfully the 2nd and 3rd jobs as listed earlier were available. This time, I decided to do each job individually to see which one actually worked. Only the 2nd job managed to do anything, proven by the re-emergence of the clunk when driving the vehicle straight after. Hence, I then decided to do the relearn procedure from Sonnax again.

After completing, I then tried the 3-2 downshift again. I was expecting it to have disappeared like last time but unfortunately, it was still there, and exactly as worse as 40mins earlier before starting the relearn!

Now we're at the present day, and I am in the following position:
1) the three jobs in tool32 are no longer available
2) the one job that works in ISTA to reset the adaptations now doesn't seem to imitate the relearn process
3) no FUB documents in ISTA not any online info can confirm the exact way to reset the adaptations and the full and correct procedure for relearning the transmission


I even spoken to a BMW technician who said this is the reason they never reset the adaptations. He advised for me to 'find a highway and start driving' which, as mentioned above, doesn't seem to work any longer.

I have contacted BMW directly, let them know of the situation, and the fact that the BMW dealership can't assist due to the situation I am in presently. Im still awaiting a response.

Hence, if anyone on the forum knows / knows someone he has the exact reset job and applicable program needed as well as the complete relearn procedure and the type of road/environment needed to relearn, I would be greatly appreciative if you could advise.

Judging by other posts by other forum members regarding the same issue, I'm sure this would not just be helping myself but many others in similar situations.

Due to the fact that he relearn performs initially was some 90% successful, I know I'm on the right track so hopefully some one knows the remaining 10%.