Launch OBD Scanner - Adventures in LKA Disabling
 

While exploring the coding variants in the Launch X431 Elite 2.0 OBD scanner, I came across some coding variants related to lane keeping assist (LKA). Getting there was by drilling down through the following menu tree:

DiagnosticsLDP abbreviates "Lane Departure Protection", which is an alternate name for LKA. Click on this and the Variant Coding screen opens. Scrolling down to item 018, the entry "LDP_UI_Variant" appears.. Clicking on this brings up a collection of 11 coding variants related to the behavior of LKA. I tried several, hoping that the corresponding screen on the G's nav screen selection "Vehicle / Assistance / Active Lane Keep Assist " display would show an LKA enable/disable option (as the owner's manual describes), but no such luck. The couple of coding options I did try only changed the behavior of the screen and enabled/disabled the key above the headlight switch that allows LKA to be turned on and off (hence the label "UI" = user interface).

https://cimg2.ibsrv.net/gimg/www.mbw...a826c8d88d.png

There was not any option I could find that was an effective LKA kill switch, but there are a couple options on this same Launch menu, located at entries 010 and 011 on the Variant Coding screen shown below. "LDP Break Intervention Enable" (should be "brake") has two options, Enable and Disable. "ALDW Warning Mode" has three options, Vibration Motor, EPS, and Sound Warning.

https://cimg3.ibsrv.net/gimg/www.mbw...59369a4af0.png


Disabling the LDP brake function and setting ALDW Warning Mode to "sound warning" (rather than EPS - electronic power steering) SHOULD render Lane Keeping Assist to nothing more than an audible warning, and eliminate the harsh braking and steering correction effects.

https://cimg2.ibsrv.net/gimg/www.mbw...1365b7ca49.png
https://cimg9.ibsrv.net/gimg/www.mbw...17596f118c.png

I successfully coded these two variants to "Disable" and "Sound Warning", but because I installed a hack on my LKA switch module that simulates pressing the button and thereby disabling LKA every time I start my truck, I have no way of testing this code change (disabling my hack involves several hours of work). Is there anyone reading this who has a Launch scanner and who is sufficiently annoyed with LKA to do this coding change and see if these coding variants do disable the most annoying aspects of LKA? Please contact me if you're willing to do this and need further information.

this does kill the LKA, but at startup there is a warning that LKA is not functioning or something along the lines. Also, there is no vibration or sound when crossing out of a lane.

I would prefer to have it active, but only with a vibration or noise. Wondering if the first step should be left to “enable”?

Hey, thanks a bunch for checking this out. My hack (which I installed a couple years ago) involved installing a small circuit that simulates pressing the manual disable button at startup. So I get the initial advisory to hold the button for 3 seconds and the follow-up message that it's been disabled, but thereafter there are no indications. Several other members have inquired about how ALKA can be coded out, but the only known option has been the MB SDS. Being able to do this with a $150 scan tool will be welcome news to many others.

Okay, some even better news! Leave it enabled, but change the second option only.

I now have lka via steering wheel vibrations only. No messages on startup since it is still active. It’s nice not having a truck that doesn’t try to wreck you when crossing the line. 👍

Okay, hold the press for a moment.

So what we know is this: with LDP_Break_Intervention_ DISABLED, LKA does not work, but you receive a message upon startup that it isn't working and you have to hight the "okay" button.

https://cimg1.ibsrv.net/gimg/www.mbw...ccf7d39b50.jpg
This is the message when it is fully disabled.

Not wanting the message on startup, I went back in and enabled LDP_Break_Intervention_. I then set ALDW_Warning_Mode to Vibration Motor.

Upon testing, that seemed to work. No message at startup and during several tests, all I noticed was the steering wheel vibrating when crossing the line.

HOWEVER, LKA seems to have come back! Very weird. Just a few moments ago, I had one instance where it applied the brake!

Rerunning the scanner, I found several errors that seemed related. I have set it back to LDP_Break_Intervention_ DISABLED.
I'm wondering if something in the following pictures may be useful in turning off the warning message that it is inoperative?
https://cimg4.ibsrv.net/gimg/www.mbw...45c758ff55.jpg
https://cimg5.ibsrv.net/gimg/www.mbw...7f9fd48c2b.jpg

In the limited testing I did, Variants 1-4 leave the LKA button operational (LKA can be enabled or disabled), and Variants 5-9 neuter the LKA button so that it has no control over enable/disable. I could not identify any difference in Variants with/without Warning on/off as far as display indications. My disable hack prevented me from observing any differences with intervention and standard/adaptive.

can this page help with what we are doing?

https://sprinter-source.com/forums/i...hreads/108445/