Cruise control not engaging

[GBJeffOH]

I have a L4060HSTC so this might be wrong. You can check the sensors on the dash.

You should get a workshop manual.

Hold down the display mode switch and turn on the key.

Mode A is to test the sensors.

 

[lugbolt]

back right side of transmission. There is a speed sensor back there. See if the wire was knocked off. Seen it happen multiple times. There isn't enough protection for the sensor and it's wiring, IMO.

 

[mpmitch1]

Update. Not 100% positive but the speedometer and cruise do not appear to be related. Upon inspection the speed sensor is broken off. I went through all of the obvious connections regarding the cruise sensors etc. When i engage the cruise lever the cruise light on the panel comes on. But the cruise will not set per manual instructions. The cruise only works if I set it by increasing rpms via the hand throttle? For ex, if I'm cruising down the road with foot throttle down and I engage the cruise and let off the foot pedal, the tractor comes to stop. But if i increase rpms via hand throttle and engage cruise while sitting still, it then starts to work,....and the further I set the cruise the faster it goes.....I can then back off the lever if I want to slow down. I'm not sure if that is correct or not but it's not the way the manual reads

 

[Bmyers]

Update. Not 100% positive but the speedometer and cruise do not appear to be related. Upon inspection the speed sensor is broken off. I went through all of the obvious connections regarding the cruise sensors etc. When i engage the cruise lever the cruise light on the panel comes on. But the cruise will not set per manual instructions. The cruise only works if I set it by increasing rpms via the hand throttle? For ex, if I'm cruising down the road with foot throttle down and I engage the cruise and let off the foot pedal, the tractor comes to stop. But if i increase rpms via hand throttle and engage cruise while sitting still, it then starts to work,....and the further I set the cruise the faster it goes.....I can then back off the lever if I want to slow down. I'm not sure if that is correct or not but it's not the way the manual reads

No, that is not how the cruise works.

You are just changing the RPM and it is reducing the flow thus reducing the speed/increasing the speed.

Yes, the speedometer and cruise are related. If it was a mechanical speed control (my great-grandpa had a mechanical speed control on his car many years ago) then the two would not be related. Yet, this is an electronic cruise, so they are related. The foot peddle in the Grand series is also electronic and not mechanical like the other Kubota tractors.

If you have eliminated all the connectors, then the next stop would probably be the computer. Yet, before you take my advice, wait till those with way more mechanical skills than mine come along to confirm.

 

[GreensvilleJay]

re: Upon inspection the speed sensor is broken off.

BINGO !!!

This is why you don't have cruise control or a speedometer.

The 'speed sensor' sends the speed of the driveshaft back to the computer, that then uses that information ( pulses per revolution ) to then control the RPM of the engine to maintain a set speed and it also 'figures out' the MPH and displays that on the screenas well.
I used 'driveshaft sensor' tech to make spreader 'computers' for Pfizer decades ago. Several tons of pellets on a huge 'log skidder' machine.needed to get precise applicarion of material up hills, down hills, etc. The 'key' was to sense the driveshaft rotation,effectivly the ground speed.

 

[jimmyjoe]

Update. Not 100% positive but the speedometer and cruise do not appear to be related. Upon inspection the speed sensor is broken off. I went through all of the obvious connections regarding the cruise sensors etc. When i engage the cruise lever the cruise light on the panel comes on. But the cruise will not set per manual instructions. The cruise only works if I set it by increasing rpms via the hand throttle? For ex, if I'm cruising down the road with foot throttle down and I engage the cruise and let off the foot pedal, the tractor comes to stop. But if i increase rpms via hand throttle and engage cruise while sitting still, it then starts to work,....and the further I set the cruise the faster it goes.....I can then back off the lever if I want to slow down. I'm not sure if that is correct or not but it's not the way the manual reads

That is how it works on my L5740. Like I said the foot pedal must be centered.. Some of the posters I think are comparing it to a 60 series tractor.

 

[Bmyers]

That is how it works on my L5740. Like I said the foot pedal must be centered.. Some of the posters I think are comparing it to a 60 series tractor.

You are correct, I thought it was 60 series, my bad. I didn't read carefully enough, must be too much eggnog.

Question though, if you have to increase the RPM for the cruise control to go faster, then how do you adjust the speed when you need to be at PTO RPM? I can be at PTO RPM and set my cruise to whatever speed I want to go. I don't see how that works with the setup you mentioned.

 

[mpmitch1]

You are correct, I thought it was 60 series, my bad. I didn't read carefully enough, must be too much eggnog.

Question though, if you have to increase the RPM for the cruise control to go faster, then how do you adjust the speed when you need to be at PTO RPM? I can be at PTO RPM and set my cruise to whatever speed I want to go. I don't see how that works with the setup you mentioned.

For the cruise to engage I Rev rpms by hand then use the pedal to move fed. At that point I move cruise lever to the middle and mph holds, if I want to move faster I move the cruise lever farther down. I CANNOT set the cruise by using only the foot pedal . For whatever reason the hand throttle must start the sequence. I tried to swap my 3240 speed sensor into the 5740 but it broke . Now I'm out 2 speed sensors . Called 5 dealers today. 2 didn't carry and 3 were closed. You'd think as vulnerable and universal as they are the dealer would carry. Try again. Tomorrow

 

[jimmyjoe]

You are correct, I thought it was 60 series, my bad. I didn't read carefully enough, must be too much eggnog.

Question though, if you have to increase the RPM for the cruise control to go faster, then how do you adjust the speed when you need to be at PTO RPM? I can be at PTO RPM and set my cruise to whatever speed I want to go. I don't see how that works with the setup you mentioned.

The engine RPM is set with the hand throttle before or after using the hand lever for the cruise control. The hand lever is used to adjust the forward speed . When the foot pedal is used it disengages the cruise control..

 

[mpmitch1]

Just got around to replacing the speed sensor. So now I have a working speedometer. The cruise control still does engage like it should. So they were not related. Guess I'll start looking at the cruise sensor.....

 

[mpmitch1]

Where is this picture? I really can't tell it's one the cruise sensors but the pic it too close!

Just got around to replacing the speed sensor. So now I have a working speedometer. The cruise control still does engage like it should. So they were not related. Guess I'll start looking at the cruise sensor.....

Is

 

[mpmitch1]

Where is this picture? I really can't tell it's one the cruise sensors but the pic it too close!

Is

Well I just swapped the cruise sensor and the pedal sensor because they are the same part number. The tractor operates the exact same......errr!

 

[mpmitch1]

Also I did mode a test. Everything checked out per manual. I'm beginning to think this is the way it is? I did notice a cruise control kit for a 3901 on you tube that has linkage between cruise control lever and pedal. I see no linkage on the 5740

 

[mpmitch1]

Dealer says this is the way it operates. Case closed.

 

[jyoutz]

My MX has a cruise control level next to the range lever. No electronics on that. It just holds the HST peddle where you set the lever.

 

[lynnmor]

My MX has a cruise control level next to the range lever. No electronics on that. It just holds the HST peddle where you set the lever.

I mentioned that possibility in post #14, it was never considered. It would be nice to know if that is the OP's problem.

 

[jyoutz]

I mentioned that possibility in post #14, it was never considered. It would be nice to know if that is the OP's problem.

It’s standard on my tractor but a dealer installed option on some other models.