2012 T870 in limp mode

[calebm]

I've got this 2012 Bobcat t870 Kubota engine that has the code e003509-04 "5 volt sensor supply voltage too low". It also takes a lot of cranking for the machine to start. Sometimes it will wear the battery dead before it starts. However, it will fire right up with starting fluid. The battery and fuel filter are brand new. Wondering if anyone has any advice? The machine has 3500 hours.

 

[mrbb]

maybe your starter is getting weak,
and have you tried checking voltage readings at starter?
as over time, wires can get corrosion both at connections and even under the insulation, which in return can lower power making it to things

and lastly, are you sure your NEW battery is actually GOOD,
I would suggest having it load tested
as a volt reading alone will not tell you its good


and after a few running it down trying to start, its possible you could have a battery cell go bad,
so even more reason to have load tested, as if its really NEW< odds are it will have a fee replacement warranty, and better to use that than pay out of pocket down the road some!

I am not a fan of using starting fluid, so go easy on it if you are

LOW compression can lead to poor starting as will many other things
low fuel pressure, BAD fuel, blocked lines and so on!

 

[PistonPete]

That 5‑volt low code makes me think it could be more electrical than fuel. If it cranks a long time and then starts with ether, maybe the ECU isn’t getting steady voltage while cranking. I’ve seen low system voltage cause weird sensor codes. On one machine I worked on, a bad pressure sensor was shorting the 5V reference line. It would crank forever and throw low voltage codes. I unplugged sensors one at a time and found the bad one. After replacing it, the starting went back to normal.