Engine just kicks down to half power 400ISL

[wsmcycle]

I'll be climbing fine, HP is up to 380 HP, and then the engine suddenly drops down to 160 HP and simultaneously down shifts. It was going 65 and now i'm down to 40 and the engine is not willing to pour on the coal. I have checked the silverleaf box and it shows the Horsepower. I don't see a fault light. Once there is a reduction in the power requirement, the engine will pick back up the power and get rolling.
This not simply an under-power problem. I went over these same hills the day before with only a little slow down but the HP remained 360-380.
There must be some signal demanding the power be cut. What could that be?

[Ray,IN]

Do you see Allison temperature? When the Allison temperature goes over a preset limit, the TCM reduces engine torque to the transmission. The TCM and ECM "talk" to each other to reduce the chance of engine and/or transmission damage.

[DGBPokes]

We had a coolant sensor cable connection go bad, and it would drop to half power.

[wsmcycle]

Thanks for that info. I will try and find something to give me the transmission temperature. I guess there are a million reason it could get high but probably the number one would be some kind of blockage of the transmission cooler air flow? Low on transmission fluid? What do you think?

[wsmcycle]

Right, so it thought it was hot but it was not?

[BrianGlenn]

The ISL has an Engine Protection Mode - different parameters can be set in the ECM to put the engine into a derate mode. Here is an excerpt from my ISL CM850. It may help understand some of the parameters that are available for monitor and engine derate.

Unfortunately, a tech with the Insite program is the only way to get into your ECM program and see all the settings configured for your specific coach. I have a printout of my coach ECM settings when I upgraded to a new flash at Cummins. Cant find it right now but I'll try to remember to look and see what my coach has for derate settings.

Hope this helps,
Brian

[Ray,IN]

Originally Posted by wsmcycle

Thanks for that info. I will try and find something to give me the transmission temperature. I guess there are a million reason it could get high but probably the number one would be some kind of blockage of the transmission cooler air flow? Low on transmission fluid? What do you think?

Of course we all know AT fluid level must be checked when at operating temp. The Allison touch pad has 2 arrows, press both simultaneously with transmission in neutral, and it will display fluid level, much easier than pulling the dip-stick with a hot engine. This pdf explains in detail.

[wsmcycle]

Brian Glenn
The manual was very good information
Thanks

[wsmcycle]

I have considered your many responses. I have a transmission error code 2214. according to the manual, this points to an engine speed sensor. MY logic tells me if the sensor is bad or has a bad connection, the error would occur constantly and i would constantly be in a condition of "engine deration". I do not have constant deration. I only have the problem when asking for as much power as I can safely have to get over a steep climb. I am using cruise and that should (i think) safely control all of the aspects.
I have observed that I am more likely (often) to fall into deration mode if i have driven hundreds of miles than I would in the first 100 miles.
The error is an "engine speed sensor". What is this engine speed sensor being compared to? Perhaps the output transmission speed is not correctly proportional to the input transmission speed and the the ECM is correct in derating the engine power. What might cause this disproportionate speed?

[Ray,IN]

An excellent Cummins resource is: quickserve.cummins.com.
You must sign up for the website, which is a wealth of information. Keep in mind, error codes mostly point to a generalized area which may be the error cause, not an exact item to repair/replace.https://mypowermanual.com/shop/cummi...system-manual/
For instance, if the sensor plug is a bit dirty and/or loose, heat from extended operation might cause the plug to lose a solid connection, which can manifest itself in a speed sensor error code.

[wsmcycle]

Thanks Ray
I will go to the Web site. The error code is from the Allison transmission. I am trying to figure out a way get up under the engine.

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[wsmcycle]

I drove up some mountains yesterday to check the transmission temp on the silver leaf. It got to 207 and after that it stayed about 200.

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[wsmcycle]

The problem is solved! It was the air filter. The little "filter minder" said it was good but it was horrible! I can't believe the power I have now. I bought it used and didn't know what to expect of its power.
THIS is beyond great!
I foolishly believed the "filter minder". The air filter was beyond horrible. It was totally [moderator edit]!
thanks to all for your help.

[Ray,IN]

Originally Posted by wsmcycle

The problem is solved! It was the air filter. The little "filter minder" said it was good but it was horrible! I can't believe the power I have now. I bought it used and didn't know what to expect of its power.
THIS is beyond great!
I foolishly believed the "filter minder". The air filter was beyond horrible. It was totally [moderator edit]!
thanks to all for your help.

There are instructions for disassembling and cleaning the filterminder and restoring function.