Cat 299d3 xe won’t rev

[Marekk2491]

Bought a brand new 299d3 with prinoth mulching head. Machine ran great for 2-3 hours and now won’t rev past 1200 rpm. It seems as if it’s electronically limited. Any idea on what would cause this? It had an alert for intake gas temperature below normal since I picked it up but ran fine for awhile prior to the issue. I’ve tried clearing the code on the display and it made no difference. I’m hoping I didn’t buy junk.

 

[heymccall]

Please convey codes as shown on display.

 

[Marekk2491]

As follows.

 

[Nige]

One of those advisories is that the engine speed has been limited due to low coolant temperature. If the engine was actually warm at that point I’d be looking for the coolant temp sensor giving a false reading.

 

[Nige]

More on the conditions that generate the advisory you are seeing. And thinking about your other fault, I would say it is highly likely that the temperature sensor that is showing the fault code has a direct input to controlling the engine RPM when the machine is "cold". Fix the SCR temp sensor fault and your limited engine RPM issue should also go away IMHO.

..........this feature also includes a warm-up period in cold start conditions. This feature limits the engine speed to certain RPMs for a short duration based on coolant temperature. This event is normal and designed to protect vital engine components. See Table 4.

 

[Marekk2491]

That’s what I was thinking. Replacing sensor now. Thanks for the help. Will keep u posted

 

[Nige]

I just threw in a diagnostic for the sensor if it will help you. See above.

 

[Marekk2491]

Thank you. Can u set temp sensor “quality flag to false” without bringing to the dealer? Am I understanding it correctly that this would by pass the sensor for now?

 

[Nige]

I suspect not.

 

[Nige]

i also suspect that the lack of the temp sensor signal (due to error or due to disabling it) would also automatically trigger the Cold Mode strategy that restricts maximum engine RPM.

 

[farmerlund]

Its brand new with 4-5hrs on it? if so why are you even messing with it. the Dealer should be getting the problem resolved. At least our local cat dealer would be.

 

[Nige]

Its brand new with 4-5hrs on it? if so why are you even messing with it. the Dealer should be getting the problem resolved. At least our local cat dealer would be.

I missed that. In that case the first call should be to the dealer along the lines of "sort this f'kin thing out pronto".

In case the salesman doidn't tell you these engines need to be run hard all the time, and not treated with kid gloves, if you want to avoid problems with the exhaust aftertreatment system.

 

[Marekk2491]

That was the first call. Like anything else it’s less about the cost of repair and more about down time. If they couldn’t get to it for a week I was going to have to fix it myself. They fixed it up.

 

[Nige]

What was the issue.? The SCR temp sensor bad..?

 

[Marekk2491]

What was the issue.? The SCR temp sensor bad..?

Yes the changes the sensor. 15 minute fix. I think your hypothesis was correct

 

[Marekk2491]

What was the issue.? The SCR temp sensor bad..?

Thank you for the help