Load Based Speed Control Issue

[SquareOne]

Would anyone know all the LBSC breakpoints which need to be raised for an X15 in CT? I see a few years back where Unilevers mentioned the breakpoint glitch, but I'm still having the LBSC affect my pulls.

I've raised all the high breakpoints to 2100 rpm (from 1800rpm), but there are also some Low 'high' breakpoint settings as well (This is how it's labeled in CT). These are set to 1400rpm and since I'm not familiar with them I left them alone. Even with the LBSC disabled and the high breakpoints raised to 2100rpm, I'm still hitting a damn wall under load at 1800rpm. Just not sure where I'm falling short at.

The Engine protection tab is locked on my ECM so I can't use Insite for this like my other truck.

[Rawze]

when load based speed control is completely disabled in the ecm then it will not matter what you set the individual settings to.

Maybe it is a different system effecting your engine?. Maybe gear-down protection or something else?.


or maybe you are simply chasing a ghost?.

Also, you assume it is LBSC.. but in all reality, it could be one of any of these 28+ limiters that are listed here in this other post ...
ref: http://rawze.com/forums/showthread.php?t...6#pid63796

======
The proper way to determine what is going on ...

If actually you want to know what is holding back or controlling your engine at any given moment then monitor the 'Fuel_Control_State' or 'CBL_Fuel_State 'setting and go from there.

look to see what the ecm is actually doing commanding, etc. ...
GET SOME desktop recording software and use this screen file for Calterm to record ALL of the settings on there.. and post screen shots of it. That will tell you everything going on inside that ECM and what that computer is doing...
ref: http://rawze.com/forums/showthread.php?t...6#pid28636

[SquareOne]

I'll go through both Insite / CT to review the settings I can get to one more time just to be sure. First thing I did when I got the newer truck was raise levels and disable the protections. I may have 'enabled' something by mistake since the program runs a bit slow on the laptop I use.

If everything checks out, I'll use what ya suggest it to monitor it through CT to see what exactly what's going on and report back.

[SquareOne]

Ok, verified that the gear-down protection has been disabled. Using CT, verified that the LBSC is inactive when I hit the 1800rpm wall. CT also gave me these figures...

'CBL_Fuel_State' : 11 - (@ idle)
8 - (anything above idle till 1800)
12 - (as soon as it reaches 1800rpm)


*** So reading through the @m*m^2 document, looks like '12' in the fueling state is the 'high-idle governor.' Now to raise that limit and we should be in business.

[Rawze]

(04-27-2023 )SquareOne Wrote:  ...
*** So reading through the @m*m^2 document, looks like '12' in the fueling state is the 'high-idle governor.' Now to raise that limit and we should be in business.

That is the max engine speed setting with zero VSS (engine not moving).

Raising the high idle governor will only make it idle up at a higher rpm when the vehicle is not moving ... and has nothing to do with the engine when it is going down the roads under load.

[SquareOne]

(04-27-2023 )Rawze Wrote:  That is the max engine speed setting with zero VSS (engine not moving).

Raising the high idle governor will only make it idle up at a higher rpm when the vehicle is not moving ... and has nothing to do with the engine when it is going down the roads under load.

The 'CBL_Fuel_State' changed from 8 to 12 while under load (top of 8th hole) going down the highway once it reached 1800rpm. Is there a max engine setting with vehicle speed that it could be up against?

Unless it's a limit with VSS and no load? When I get to 1800, it's very gently... Didn't know if there was a particular engine load required to pass that rpm threshold.

[Rawze]

(04-25-2023 )SquareOne Wrote:  Would anyone know all the LBSC breakpoints which need to be raised for an X15 in CT? I see a few years back where Unilevers mentioned the breakpoint glitch, but I'm still having the LBSC affect my pulls.

I've raised all the high breakpoints to 2100 rpm (from 1800rpm), but there are also some Low 'high' breakpoint settings as well (This is how it's labeled in CT). These are set to 1400rpm and since I'm not familiar with them I left them alone. Even with the LBSC disabled and the high breakpoints raised to 2100rpm, I'm still hitting a damn wall under load at 1800rpm. Just not sure where I'm falling short at.

The Engine protection tab is locked on my ECM so I can't use Insite for this like my other truck.

If you are trying to convert an X15 program that is set factory max for 1800rpm into one of the 2100rpm programs, I can tell you that there are roughly 40 settings required to get it right.

Everything from axis headers on several tables like fueling, etc.., to governed settings, to gear-shift control, accel. pedal settings, etc.

There is no single or simple master 'rpm setting'... that can do it correctly, just like there is no 'off' settings for the egr or other systems.

Even if you manage to get the thing to run at higher rpm.. many of the tables like fuel pressure, fuel limiting, torque, etc.. can run start to out of steam (table just does not go high enough) and hold it back.


I have a template that I use/made for doing this correctly. I usually do not apply it to someone's program unless they want me to specifically.

[SquareOne]

It's not absolutely necessary as I don't pull long grades like many of the guys here, I just like to bring it up high in rpm, when I'm at gross, with as little throttle input as possible. After driving my other truck and touching 1900-2000 between shifts a handful of times a week when heavy for the last 450k miles, its def an adjustment to be limited at 1800 lol.

Truck does fine just like it is, so again, not a huge deal.

Thanks for explaining, as I didn't realize the amount of adjustments required to obtain a higher rpm. I guess with anything ecm related, nothing is as simple as it may seem.

[Rawze]

(04-27-2023 )SquareOne Wrote:  It's not absolutely necessary as I don't pull long grades like many of the guys here, I just like to bring it up high in rpm, when I'm at gross, with as little throttle input as possible. After driving my other truck and touching 1900-2000 between shifts a handful of times a week when heavy for the last 450k miles, its def an adjustment to be limited at 1800 lol.

Truck does fine just like it is, so again, not a huge deal.

Thanks for explaining, as I didn't realize the amount of adjustments required to obtain a higher rpm. I guess with anything ecm related, nothing is as simple as it may seem.

Who knows for sure why they did the X15 programs this way... the older model engines such as CM871's for example, had some extra leeway for the upper rpm limits for most tables, ect., but many of those X15 programs simply are clamped off at lower rpm on these same tables, and not just at the speed limiters.

(X15 - 1800 program on the left, 2100 program on the right. the J1939 broadcast torque settings are shown here)

just one example of many places in the program where this was done.