NefMoto

I'm working on a Volvo with my friend, forged 2.5T, hybrid turbo, yadda yadda yadda.

We switched to Focus RS MAF, as we were approaching the limit of stock MAF sensor.
After we replaced MAF, we upped the load request, but something strange started to happen, the throttle would start to close when the mass air flow was crossing approximately 950kg/h threshold, also the lambda request was going straight to 0,7. It is not overboost related.
Upping thresholds in KFMLDMX, MLDHFMKO doesn't do anything.

The DTC read by Vida states ECM-122C MAF Flow Too High, the DTC corresponds to HFME fault class, so it would mean an electrical error (?)

Comparing the Focus RS file and our Volvo file I can see that electrical diagnosis of the HFM and also the flow diagnosis is a little different. But I'm stuck right now with no idea what to do next.

In the link you can find both Focus RS software with A2L and Volvo bin with .kp file for WinOLS, also included is Volvo .idb for Ida PRO with some memory addresses labeled (probably contains errors).

If someone could at least guide me in the direction what to look for I would be really grateful.

Thanks in advance!

LINK: https://drive.google.com/file/d/1pQjRK6flCbhE07feMGmHNHISQukLP99r/view?usp=share_link (https://drive.google.com/file/d/1pQjRK6flCbhE07feMGmHNHISQukLP99r/view?usp=share_link)

You have to modify KFMLDMX map. And maybe MLmax value.

KFMLDMX was modified, MLMAX appears to not be present in this software. But I can be blind.

Function at addr 0xFDD24 returns diag data from get param by index command. It's very useful function for reverse engineering. It's Volvo specific command. I didn't find anything equal in Audi's software. Maybe Ford's has such function.

There is more checks on HFM inside Volvo ME9. Check MLDHFMKO value.

Also changed those values, still the issue persist.

And this value UHFMMX at addr 0x1C3EA6?
Threshold for uhfm max failure during 1ms test.
Value from Volvo ME9 binary is 4,9023

I can't open your kp file due to being a newer version so I can't see what's done but when I did my RS4 MAF, I did the following:
Translated over the MSHFMU and set KFKHFM all to 1. (All fueling is done via FKKVS. That is the same as with the Focus RS from factory, even the RS4.)
You also need to set CDEHFM to 0 to disable diagnosis.
Of course KFMLDMX, MLDHFMKO, MLDHFMKU and KFMLDMN have to be adjusted.

No, you don't. You need to adjust the thresholds correctly.
Disabling diagnosis means if your MAF dies you are stranded, pretty dumb.

I was disassembling the Volvo file and comparing it with Focus RS with memory locations loaded from A2L(thanks for the script prj). Haven't found UHFMMX in my file, or at least I can't see it. Also we are not approaching 4,9v with our current flow and MAF housing with Focus RS insert in. But I will look into it some more. Thanks for all of your help.


I did everything that you mentioned apart from setting CDEHFM to 0.

And if you do that, then if your MAF fails or a hose pops off you will most likely be stuck with a non-startable car in the middle of nowhere...

Can you share stock and currently modified file?
Stock is in first post, but show also the mod, maybe some simple mistake.

I'm well aware of that and I want to do it properly :)



See the screenshot attached, I can't find UHFMMX in my file. It is present in Focus RS binary.

In your file the GGHFM module does not have UHFMMX and UHFMMN.
But post modified file.

I have posted before you edited your post. Here is the modified file.

I think you misdefined a bunch of shit and then went over it with a sledgehammer...
I fixed the MAF part, I didn't look at anything else.

Yup, I started defining the .kp before throwing everything into IDA and making sure about placement of all maps and I understand that the definitions are a mess. I'm very thankful for your time and help :)

EDIT: I'm also eagerly waiting for support of Volvo ME9 in your logger, it will help a lot!
EDIT2: Looking at it I have just made a mistake with MLDHFMKO and MLDHFMKU in the version that I've sent, rest was carbon copy from Focus RS bin. But will test and report.

That is weird. My car still starts and runs (but on limp mode) even with MAF disconnected with CDEHFM on 0. I turned it off as I keep getting a MAF error on VIDA (no check engine light) but you can definitely leave it on.

@prj, flashed your fix, still the "limp" occured and the error code came back

@cheekano, also tried setting CDEHFM to 0, but then the boost solenoid duty cycle stayed at 0%

Consider this issue on hold, for now I'm waiting for prj logger to properly check what's going on in the ECU. Unfortunately VIDA/Volvo DHA doesn't give any useful information.

You can log memory of P1 ME9 with this tool https://github.com/prometey1982/VolvoTools
So you can find the reason why the error is set.

Sent you a PM, but if there is any other more comfortable way to communicate with you I would like to switch to it.

I released the Volvo ME9 logging in my tool. Both D2 and UDS.
Ford ME9 has been supported for a while already as well.

Is there security access required for Volvo or Ford ME9?

Ford yes.
Volvo no, it's open. You only need to pass security if you want to read from the flash.

Ford comms stack is completely different.

Issue fixed and the culprit is shown on the screenshots below :)

Good job.