2014 M126GX RPMs won't Rev up and Tractor Won't Accelerate

[SouthFL]

Good Morning,

I have a 2014 M126GX. For whatever reason when I am in Neutral and press the accelerator the RPMs do not go above idle. When I put it in any gear L, M or H and press the accelerator it does not accelerate. The only way to go faster is by increasing the gear. Yet it stays at idle rpm. Any recommendations?

Thanks

 

[jonsstihl]

does the hand throttle increase the RPM? sounds like your throttle cable snapped or is disconnected. I doubt a 2014 tractor uses fly by wire technology but if it does it may be sensors that are affected instead of a cable.

 

[SouthFL]

does the hand throttle increase the RPM? sounds like your throttle cable snapped or is disconnected. I doubt a 2014 tractor uses fly by wire technology but if it does it may be sensors that are affected instead of a cable.

It does but very slightly. It doesn't go up much and no where near full range.

 

[jonsstihl]

I would start with checking cable connections at the injection pump if it is not fly by wire.

 

[SouthFL]

I would start with checking cable connections at the injection pump if it is not fly by wire.

Great. Appreciate the input. I'll get to it the next day or two! Thanks!

 

[MHarryE]

The foot and hand sensors are completely separate. It’s difficult to explain without you having the diagram. There is a procedure for checking the voltage to each sensor but since both quit at the same time you can probably rule these sensors out as the problem.

Are you sure you did not turn the rev limiter dial to a low engine speed? Your symptoms would suggest the rev limiter control is set very low, the reason you get very slight engine speed change from either of the 2 separate signals. The engine speed is normally controlled by the higher signal from either the hand control or foot control - up to the voltage limited by the speed limiter dial.

My first thought would be a problem with the speed limiter control. When turning the dial, the resistance across the terminals 2 and 3 on the connector should vary from 0 to 1k ohm. On the harness end, with the key on, the terminal should read about 5v.

The voltage return to the engine ECU is determined by the higher of the signal from the foot pedal or the hand control, but only up to the limit set by the speed limiter dial.

 

[jonsstihl]

sounds like the tractor is fly by wire from someone who knows way more about your specific tractor than me. go with what he said. my guess is you hit the rpm limiter by accident and it is something simple. Hope you have the owners manual. Sounds like a simple fix.

 

[SouthFL]

The foot and hand sensors are completely separate. It’s difficult to explain without you having the diagram. There is a procedure for checking the voltage to each sensor but since both quit at the same time you can probably rule these sensors out as the problem.

Are you sure you did not turn the rev limiter dial to a low engine speed? Your symptoms would suggest the rev limiter control is set very low, the reason you get very slight engine speed change from either of the 2 separate signals. The engine speed is normally controlled by the higher signal from either the hand control or foot control - up to the voltage limited by the speed limiter dial.

My first thought would be a problem with the speed limiter control. When turning the dial, the resistance across the terminals 2 and 3 on the connector should vary from 0 to 1k ohm. On the harness end, with the key on, the terminal should read about 5v.

The voltage return to the engine ECU is determined by the higher of the signal from the foot pedal or the hand control, but only up to the limit set by the speed limiter dial.

I'm pretty sure I didn't but I'll take a double look and check. I had the loader parked for a few years letting a buddy use it before I finally got it back to my place. I'm going to get back out on it tomorrow and I will take a look at everything you've mentioned. I appreciate the response!

 

[SouthFL]

sounds like the tractor is fly by wire from someone who knows way more about your specific tractor than me. go with what he said. my guess is you hit the rpm limiter by accident and it is something simple. Hope you have the owners manual. Sounds like a simple fix.

I do have the owners manual. I appreciate your response as well. I wish I could get my hands on the electrical diagrams as well lol

 

[5030]

Shop manual will give you the schematics for the wiring.