Genie 5519 - Suddenly drops to idle and throws codes

[Makers Acres]

Just got my 2016 Genie 5519 up and running after a rebuild. I ran it for couple of times and noticed once that the engine dropped to idle and threw two error codes:

SPN 91 and
FMI 11
which translates to
"Plausibility error between APP1 and APP2 or APP1 and idle switch"

I noticed that the throttle pedal was kind of sticky so I took this opportunity to take it all apart, cleaned it and re-grease the friction points.

Put everything back together and it ran fine a few more times, but now it is starting to throw the messages again. What's more is that it seems to get worse as the engine heats up. It will drop to idle, then I have to shut it down and wait 5 minutes, and then I may be able to run the machine for a few more minutes before it drops to idle again. Sometimes this takes a few tries before it comes back to working order.

Anything thoughts on troubleshooting this?

My next action was going to be pull the assembly out and try to identify the pins, then connect it to my scope and see if I can see anything strange.

I am assuming this is a problem in the throttle pedal, or is there a secondary idle switch that might be on the engine somewhere that I am not thinking about?

Thanks!

 

[Txhayseed]

Throttle sensor has two separate sensor basically in one housing. You have the idle circuit switch and off idle validation. Im sure you already pulled the schematic since you rebuild the machine as you did. Is it a williams brand tps ? If so Cummins has a very good TSB that breaks down the sensor and signals as well as a very good diagnostic trouble shooting guide. Those sensors are widely used by several manufacturers in the industry.

 

[Makers Acres]

I don't have a schematic for it unfortunately, so here is a picture of the sensor. I am sure it is re-branded, but this makes it hard to figure out what it is.
Any ideas? Thank you for your help!

 

[Txhayseed]

These are tuff ones. We had a batch of brand new reach forks that did the same thing. They would run, then drop the pedal out and you could only idle no throttle. Restart unit and sometimes they would work fine for days after sometimes for 20 minutes. We replaced a lot of tps sensors via manufacturers suggestions but same issues. Then it was oh the wiring has to be bad.. So long story short these type of gremlins are tuff. Being that it is a hall effect sensor and you cant recalibrated it its possible its just getting to the point where it looses reference randomly. The ecm needs to see a closed ivs signal before letting the throttle go off idle. Then to complicate it more there is a threshold say 20% ( manufacturer specific) throttle input before the ivs sends signal. Plus if you have any noise over the can line they freak out . Check your wiring really well. Pins, plug ect. I would look online and see if you can source a sensor for cheap and use it to test the bad sensor theory. The genie schematic should show you the pin out on the sensor.. Sorry could not be more specific to help narrow it down other than the above mentioned

 

[Makers Acres]

No, that is great info and I appreciate all of it. Pretty much all of the wiring was replaced in this unit too. I would estimate this pedal probably has less then 100 hours based on when the machine caught fire. I am capable of putting a scope on this and checking things out.
I would say they problem has gotten worse. I tried running it last night and was only able to travel a few feet before it shutdown again.
When I took the sensor off the pedal, it does appear that the rod into the sensor can spin 360 degrees and can be put back together 180 degrees out of phase if I want to. Makes me wonder if I did that correctly the first time, but then I don't think it would work at all if that was the case.
What ended up solving your problem?

 

[Txhayseed]

We ended up making new harness ourselves.. About 80% of the time that solved the issue. Drive by wire sensors are just a horrible invention. If you have a scope I would definitely check and see what the lines look like. It takes very little to upset the transfer rate.

 

[Txhayseed]

But just for reference the code i failed to comment on would be an issue between idle and off idle validation. You could check that with your meter when the code pops.

 

[Makers Acres]

This morning I traced the wires out and pulled the connector off the Engine Control Unit and connected it to my scope. The signals look really good and strong. I checked the IVS (idle validation sensor). and these signals always appear solid and triggering at the correct time. I tried wiggling and flexing parts of the cable while performing these tests and it all seemed very solid. So I am not sure where to go next. My next option is to try and connect the scope to the wires while they are connected to the ECU, but that is going to require disassembling the wiring harness, so I am not to keen on that idea.

 

[Txhayseed]

Did you get the code to repeat after all your testing ?

 

[Makers Acres]

Yes, It still is constantly happening. After talking to Genie, they seem to think the ECU might need to be reprogrammed to match the values on the throttle switch. I don't know what to believe at this point.

 

[Txhayseed]

Possible. Ecu's can do some crazy stuff. Glitching like it is does not sound like an ecm issue to me though. But getting ecm reflashed with the most current reversion couldn't hurt and would rule it fast

 

[Makers Acres]

I replaced the throttle Pedal and that did not help either. They problem is now that I can’t find anyone who can flash the unit.
I have talked to Genie support and they have no idea how to fix the issue.
One thing I did notice is that my idle is higher then what the manual says it should be. So I am wondering if that might be causing an issue as the throttle crosses the IVS threshold? Just tossing out ideas. I don’t see anyway to adjust the idle on this unit though without a computer.

 

[Txhayseed]

You cant with out software. How high is your idle ? The ecm controls idle speed. It could cause an issue transitioning from of idle validation since it would be at the upper end of the range. Are you still getting the same codes as before ? Where are u located ?

 

[BigWrench55]

I would check the throttle body. If it's values are not the same as the pedal you will get this problem. A sticky butterfly valve could be the problem. Soot could be stopping the valve from resting at its idle position. Since you have a scope then you can easily verify this. There are two sensors at the pedal and two at the throttle body. All four basically validate each other 16 times before any action takes place. It's a built in redundancy so that you don't go wide open throttle into wall or something horrible like that

 

[Makers Acres]

You cant with out software. How high is your idle ? The ecm controls idle speed. It could cause an issue transitioning from of idle validation since it would be at the upper end of the range. Are you still getting the same codes as before ? Where are u located ?

Yea, still get the same error code. It idles around 1160-1200. When it throws an error code and locks the throttle out, it drops to around 960. I noticed in the manual it calls for an idle of around 900 as well. With this higher idle which I engage a direction it also "Creeps" so I think my idle is probably too high.
I am located near Burbank California.

 

[Makers Acres]

I would check the throttle body. If it's values are not the same as the pedal you will get this problem. A sticky butterfly valve could be the problem. Soot could be stopping the valve from resting at its idle position. Since you have a scope then you can easily verify this. There are two sensors at the pedal and two at the throttle body. All four basically validate each other 16 times before any action takes place. It's a built in redundancy so that you don't go wide open throttle into wall or something horrible like that

This is a hard machine to find the Throttle assembly as this is the first unit I have owned that is "Fly-by-wire" or completely electronically controlled.

 

[BigWrench55]

This is a hard machine to find the Throttle assembly as this is the first unit I have owned that is "Fly-by-wire" or completely electronically controlled.

The throttle body should be on the engine where the charge air pipe comes in.

 

[Txhayseed]

There is no throttle body. Fca on injection pump meters fuel demand based on input from ecu that maps fuel rate based on throttle sensor. Throttle position sensor or your pedal is like the " throttle body" your ecm is programmed with an external throttle input. The off idle validation, max throttle are built into the fuel map from the OEM. The ECM from deutz can be end user configured to run multiple throttle inputs to facilitate one engine being used in any thing from a welder to a pump to a forklift. To get into that you will need software.

 

[Txhayseed]

As far as idle goes there is usually a small variable built it. It says 900 but there is a plus/minus since idle rpm can vary depending on conditions like humidity/altitude ect. The ecm makes those corrections as needed but it does not freak out if the idle rpm is not set at a certain rpm as long as all sensors are reporting parameters are met.

 

[BigWrench55]

I don't know what deutz's nomenclature is for it. But I was referring to the inlet valve that controls the airflow to the engine.