*Solved* RPM dip then car dies ONLY when AC on after airbox tune

[karter16]

Can he use that with a non-HP?

oh wait - so we're talking standard M3 tune here? or CSL tune?

[Slideways]

oh wait - so we're talking standard M3 tune here? or CSL tune?

My guess is standard tune since he said MSS54 with Alpha-N and I think it is an earlier car.

[karter16]

My guess is standard tune since he said MSS54 with Alpha-N and I think it is an earlier car.

Thanks for pointing that out and apologies then - my post can be ignored - I misunderstood when I read OPs current setup.

[ugaexploder]

karter16, i worked with OP to remove the smg VO coding $793 from the list.. any idea as to why in technical terms this could cause the car to stall?

my car used to do the exact same thing, and also nextlvel had this issue as well. both of ours has been resolved after removing the $793 from VO list but i have no explanation why this worked or why it would cause this problem…i think OP is going for an extended test run to see if the issue still happens..i’m truly convinced this is the issue with most smg-to-6spd conversion cars but can’t really explain why

[sbay]

Solved?

Huge shoutout to ugaexploder for helping me code out $793 on NCSExpert. I actually never knew how to do anything coding related but I learned because I wanted to fix this. I had went to a local shop to get the manual swap coding done and lo-and-behold the $793 code was still active on my car. Getting Windows XP, watching the 50sKid, reading 10 year old threads, and going to Harbor Freight to buy a soldering iron to solder pins 7 and 8 on my DCAN cable just to get this all done was all worth it, even if just to know how to use INPA and NCSExpert now. I’m going to give it some time as I reset adaptations before I consider this solved, but I’m hopeful. And if it doesn’t work, at least I learned a thing or two.

P.S. Anyone else a fan of Olive Green on XP?

[karter16]

karter16, i worked with OP to remove the smg VO coding $793 from the list.. any idea as to why in technical terms this could cause the car to stall?

my car used to do the exact same thing, and also nextlvel had this issue as well. both of ours has been resolved after removing the $793 from VO list but i have no explanation why this worked or why it would cause this problem…i think OP is going for an extended test run to see if the issue still happens..i’m truly convinced this is the issue with most smg-to-6spd conversion cars but can’t really explain why

Without knowing for sure my speculation would be around the fact that modules such as DSC obtain data from the SMG module. If one of those modules is expecting data that isn't arriving, or it's expecting to receive data from SMG rather than however it receives the info in a manual car then that could cause issues with how things are being calculated. Likewise it might be the DME is still expecting data over SMG CAN that never arrives, and it ends up in a failsafe situation that's different to how it handles a simple manual gearbox situation.

[sbay]

Without knowing for sure my speculation would be around the fact that modules such as DSC obtain data from the SMG module. If one of those modules is expecting data that isn't arriving, or it's expecting to receive data from SMG rather than however it receives the info in a manual car then that could cause issues with how things are being calculated. Likewise it might be the DME is still expecting data over SMG CAN that never arrives, and it ends up in a failsafe situation that's different to how it handles a simple manual gearbox situation.

My guess on that is in the difference in behavior I’m now noticing. Now when pulling in to a stop, or any situation beforehand that would result in the idle dip, the car will now hold idle at ~1k rpm until I make a complete stop and then it will idle down to a normal idle. Before it would not search or stop at that 1k rpm and would just keep dwindling down until it dies or I blip the throttle. My guess is there was some communication with the SMG module letting the ICV know it’s in neutral for it to steady that 1k rpm until a full stop. Since there was no SMG module, ICV never got the neutral message, and failsafe activated. Again this is me just theorizing off behavior change without any proof with data

*edit* I just don’t know why the AC forces this problem more often, and why it happens intermittently versus at every stop, but maybe it has to do something with the load the AC forces which naturally creates more idle surges? I’m still giving it a few more test drives before making this solved but so far the problem hasn’t come back

[chris719]

I’m not sure if this is related at all. I have experienced the same thing on my Z4M and it’s got a stock airbox and stock DME tune.

[rockstar b]

A step by step on this would be amazing. I had chalked this up to regular old car / IAT on a hot day / heat soak issues, but I really need to check my VO to see if that code is still in there. I’m sure I could handle removing the code, but the reflashing stuff may be a bit over my head.

[ugaexploder]

I’m not sure if this is related at all. I have experienced the same thing on my Z4M and it’s got a stock airbox and stock DME tune.

A step by step on this would be amazing. I had chalked this up to regular old car / IAT on a hot day / heat soak issues, but I really need to check my VO to see if that code is still in there. I’m sure I could handle removing the code, but the reflashing stuff may be a bit over my head.

are both of your cars smg-to-6spd conversions? i believe this fix would only apply to those who had the manual conversion done on their car.

to remove $793 code from your VO, you would connect using a K+DCAN cable with pins 7 and 8 bridged. i just purchased one off amazon with a toggle switch to make life easier, but if you already have a cable just check to see if pins 7 and 8 are jumpered or else you get a "faulty VIN" notification while trying to connect with NCS expert.

while not absolutely necessary, I'd recommend having your car connected to a trickle charger just to avoid the small possibility of the car battery dying during the process. probably good practice to do this anytime you are doing any sort of flashing or coding. you can get away with using a 1A charger, but 10A is better.

there are some good how-to guides on getting BMW standard tools installed on your pc/laptop.

https://www.e46fanatics.com/threads/installing-bmw-standard-tools.1322014/

link below is a sticky on the forums that gets you going with NCS expert

https://nam3forum.com/forums/forum/special-interests/coding-tuning/1281-getting-started-with-ncs-expert

the below is straight from terra's sticky topic:

VO / FA Changes:

Occasionally when looking up a DIY, you might see mentions of adding an option code to your VO. This will discuss how you go about that. (ZCS Changes will be discussed later).

• Go back to the FG/ZCS/FA screen mentioned earlier.
• If you haven’t already done so, read out the VO from your car.
• Now click “Enter VO/FA”. You might be prompted to select the chassis again, in which case choose the right one.
• You’ll now get a window to enter the VIN. It should be pre-populated, hit okay here.
• Now you’ll get a window labeled Enter VO/FA like below. This is where you can make changes. To add a VO code, type it in the box, and click the “Add” button. To remove a VO code, select it from the list, and hit the “delete” button on your keyboard (or if you’re on a mac, Fn + Delete).
• For the purposes of this guide, let’s say you want to retrofit LED Taillights. What you’ll do is type in “+LEDH” in the box, and click add. Now hit “OK”.
• From this point, NCS Expert will be basing its coding decisions based on the VO you entered, not what the car has stored in its modules.
• Now there are a few things we need to do. We want to store this modified VO in your car’s modules, and then we want to actually code the module(s) of interest with your new VO. So let’s start with storing the new VO.
• Click “Process ECU” choose the AKMB module
• Click “Change Job” and select “FA_WRITE”. Execute that job.
• Now click “Change SG/SGET” and select your “ALSZ” module. The FA_WRITE job should still be selected, but if it’s not, change the job to that. Hit “FA_WRITE” again.
• Now we have to code your car for the new VO. In this case where we’re doing an LED retrofit, I know the only module impacted is the ALSZ module. So we don’t have to select a new module this time.
• Open up your FSW_PSW.MAN module, and delete everything inside of it. Now save that file. Alternatively you can open and then close NCS Dummy. It will prompt you to blank out the FSW_PSW.MAN file if it isn’t already.
• Change the job type to SG_CODIEREN, and hit execute job.
  • Since your FSW_PSW.MAN file is blank, NCS Expert will determine how to set every option in your ALSZ module by your VO. After that’s done, your car will now be coded for LEDs.
  • If you had previously customized your ALSZ module, you’ll lose the customizations you’ve made, so you’ll have to add those back by hand.

Below are steps from google AI:
Step 1: Prepare NCS Expert

1. Connect your cable (e.g., K+DCAN) to your car's OBD-II port and your laptop.
2. Turn the ignition key to position 2.
3. Launch NCS Expert and load the Expert Mode profile.
4. Press F1 (VIN/ZCS/FA).
5. Press F3 (ZCS/FA f. ECU).
6. Select your chassis (e.g., E89 for E9x models) and click OK.
7. Select the CAS ECU and click OK.
8. The main window will now display your VIN and current Vehicle Order (VO/FA).

Step 2: Delete the VO option

1. Press F2 (Enter FA) to modify the VO.
2. Confirm your chassis and VIN in the pop-up windows.
3. The Vehicle Order list will appear. Find the $793 option in the list.
4. Highlight $793 and press the Delete key on your keyboard to remove it.
5. Click OK to confirm the deletion.

Step 3: Write the new VO to the CAS and FRM/LMA

1. After deleting the code, press F6 (BACK) to return to the main menu.
2. Press F4 (Process ECU).
3. Select the CAS ECU and click OK.
4. Press F2 (Change job).
5. From the list, select FA_WRITE and click OK.
6. Press F3 (Execute job) to write the new VO to the CAS module. Wait for the process to complete.
7. Repeat this process for the secondary VO storage module. Press F1 (Change ECU), select your FRM (E9x) or LMA (older models) and click OK.
8. With the FA_WRITE job still selected, press F3 (Execute job) to write the new VO to the FRM/LMA.

Step 4: Code the affected modules

1. After the VO has been updated, you must recode any affected control modules to adopt the new settings.
2. Press F1 (Change ECU) to select the module to re-code. In the case of $793 (related to SMG/transmission), you may need to recode the Instrument Cluster (KOMBI/AKMB) and other drivetrain-related modules.
3. Press F2 (Change job), select SG_CODIEREN, and press OK.
4. Press F3 (Execute job) to code the module based on the new VO.
5. Repeat this process for any other modules that were affected by the removal of the VO option.

Step 5: Verify and finalize

1. Turn the ignition off and on to reset the modules.
2. Check for any error messages and test the functionality that was changed by removing $793.

[rockstar b]

Awesome! Yes, mine is a SMG to M6 conversion, and Go Dawgs!

[sasha]

Have you completed a drive cycle? I brought my car from Denver to TX and the codes also go wiped and my car's idle would dip every time the HVAC engaged the compressor clutch (which is really often btw... like every 30-sec). After a drive cycle its not too bad anymore.

[sbay]

Unfortunately, the problem is still there. Going to start with smoke testing and go from there at this point

[Bry5on]

Have you tried fuel tuning your RF map? This could easily happen if your engine runs rich at normal driving rpm/loads and lean in a couple cells around engine idle load with AC on. Your fuel trims could be pulling fuel while driving, then when you go back to idle it’s too lean to recover quickly. Blipping the throttle could give it just enough fuel to let the fuel trim come back to a range that lets it idle. Just a thought, though it’s hard to diagnose a modified and tuned setup.

[sbay]

*SOLVED*

So turns out, the fault was with the manual swap coding and finding a thread by nextelbuddy.

https://nam3forum.com/forums/forum/special-interests/coding-tuning/246025-ecuworx-issue-with-clutch-switch-direct-wire-and-gps-delete

0x67E0 was 80 instead of A0…no more stalling, we’re back in business boys