L3540 HST driving strange - Swash Plate Sensor fix

PeaceOfPrairie

New member

Equipment
L3540 w/ Loader +Selector valve for rear remotes
Jun 23, 2019
1
0
1
Muskogee
Hi Orange gang,

Long time lurker - I've saved so much money with fixes and advice from this forum. I just fixed my hydrostat error, and thought I'd share.

Symptom: Hydrostat pedal in Neutral, but tractor is moving as if it's about 1/3 depressed in the forward direction. I had to hold the pedal 1/2 way into reverse to keep it sitting still. Very dangerous situation! It would lurch unexpectedly when it pulled itself back to the regular neutral position. When it was driving itself (pedal in neutral, moving bout 1/3 of full speed), it would kind of slow-down then lurch about every 2 seconds. A pulsing sensation.

I had replaced the cruise control sensor the year prior, so I figured it was failure time for the hysdrostat pedal sensor. I bought a new hydrostat pedal sensor, and installed it. No change.

A few weeks pass driving wildly. I read online that the swash plate sensor could be a source of trouble. I read through the Workshop manual (can find free online if you dig hard enough, or pm me to share) I learned how to use the the diagnostic voltages in the dash computer - I checked out the pedal sensor and swash plate sensor - everything seemed to check out.

A few more weeks pass. Finally the computer throws an 82 code - swash plate sensor, but it only did it one time, never again. I ran the diagnostic voltages again, and one of the "sub" voltages seemed just a little off. More reading said to check the connections at the swash plate sensor. I unplugged & cleaned, and finally it gave me a consistent 82 - Swash Plate Sensor error.

I couldn't find the swash plate sensor in the parts lookup for the life of me. I had the old, but functioning pedal sensor that I had replaced, and hey, they look exactly the same.

I installed the pedal sensor in place of the swash plate sensor, plugged it in, and no errors! It's been running fine for a week.

Swash Plate sensor is apparently interchangeable with pedal sensor (and likely the cruise lever sensor) - makes sense that they'd use the same part for simplicity.

Thanks again for the time and expertise you all put into this site!
 

200mph

Well-known member

Equipment
L4740-3 Cab, FEL, Fnt Snow Blower L2185, LP Finish Mower, LP Rotary Mower
Mar 3, 2017
1,228
59
48
PA
Thanks for sharing!
 

D2Cat

Well-known member
Lifetime Member

Equipment
L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
13,003
4,383
113
40 miles south of Kansas City
PeaceOfPrairie, thanks for in heads up.

Welcome to the forum. It is very unusual the first post by someone is offering help. Most often it's looking for the solution!
 

200mph

Well-known member

Equipment
L4740-3 Cab, FEL, Fnt Snow Blower L2185, LP Finish Mower, LP Rotary Mower
Mar 3, 2017
1,228
59
48
PA
According to the WSM there is a difference between the HST Pedal Sensor and the Swashplate Position Sensor. They do look the same, but they have different part numbers. Here's what the WSM states:

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