X15 2450 low power high fuel consumption

[Rawze]

(11-19-2023 )Will144 Wrote:  Just looked up the code in work orders. New one is KW10431.06 the old one is KW10091.04. I asked the dealer to put the old one back in to try it. They said they couldn't. I'm not sure how to do that part myself. I'm using a company truck until I get it fixed right. Just don't need to burn it up by driving it when it's sick.

The differences between program KW10091 and KW10431...

== The 'Road Speed Look-ahead' feature is ON in the KW10091, but is OFF in the KW10431.

== The KW10431 program allows for slightly more fueling between 1600 and 1900 RPM with regard to base engine operating modes, SCR and DPF temp control modes, and for After-treatment oxygen limiting situations.

== The KW10431 program asks for (about 5%) less EGR gas between 1000 and 1200 rpm below 4,000 feet altitude.

== The KW10431 program asks for (about 12%) less EGR gas when it is running in engine operating mode 13 (SCR moderate warm-up mode). It calls for more aggressive charge flow (slightly higher boost) in this same operating mode, and it also has sightly higher fuel pressure requests in this mode as well.

Aside from what is mentioned above, the main EGR requests are identical.

== Injection timing has been reduced (by a couple degrees.. which is a medium-large change for a CM2450) in 3 of the engine operating modes. These modes are ...

++ (mode-A0) cold-start/engine overload.
++ (mode-13) SCR moderate warm-up mode.
++ (mode-3) extreme altitude EGR+ operating mode.
In all other operating modes, the injection timing is the same.

== The torque fuel conversion has been altered in several engine operating modes. This will directly effect 'how the engine accelerates and feels'. The changes are...

++ (mode-A0) cold-start/engine overload: The power has been made MORE aggressive in the KW10431 program.

++ (mode-A1) low-altitude EGR+ mode: The power has been made LESS aggressive in the KW10431 program, and will feel slightly weaker.

++ (mode-2) high-altitude EGR+ mode: The power has been made MORE aggressive in the KW10431 program, and will feel slightly stronger.

++ (mode-3) extreme-altitude EGR+ mode: The power has been made MORE aggressive in the KW10431 program, and will feel slightly stronger.

++ (mode-11) agressive SCR temperature management mode: The power has been made LESS aggressive in the KW10431 program, and will feel slightly weaker.

++ (mode-13) SCR moderate warm-up mode: The power has been made quite a bit LESS aggressive in the KW10431 program, and will feel moderately weaker.

== The coast manager idle speed used for auto-trannies with 'coast' feature is set to 500RPM in the KW10431 program and set to 600rpm in program KW10091. Personally, I think that 500rpm is too low, and will cause the top-end to easily get starved of oil in the engine while in this state.

== There are quite a few changes in the mis-fire detection manager between the 2 programs. The changes are not subtle.

== In the KW10431 program, there are extra (and some more aggressive clamping) EGR flow monitors/restrictions that are switched on in the UFM (Universal Flow Manager) circuit. This is extra hi-flow, low-flow, accel limiting, and other limiting based no these extra flow restrictions. There is also a EGR flow 'noise restriction' that is set much more intolerant in the KW10431 program. I suspect these changes would negatively effect acceleration rates by some degree .. but that is speculation.

== The engine CPL changes from 5479 (KW10091 program) to CPL 5869 (KW10431). The CPL change seems to be related to a different fuel code par# mostly.. however all fuel pump, etc. settings are identical to both programs.


All else in the programming is identical between the 2. They are 100% compatible with each other as a whole, but the KW10431 does seem to have more aggressive EGR restrictions, more sensitive cylinder mis-fire detection, and slightly less power output settings for some of the engine operating modes, as mentioned above.