CODE 81

   / CODE 81 #1  

jenkinsph

Super Star Member
Joined
Feb 27, 2008
Messages
12,567
Location
somewhere usa
Tractor
Deere 110tlb, 4520, x749, L130
Hey guys I Am getting a code 81 on my 4520. Can someone tell me what it is? Thank you.
 
   / CODE 81 #2  
Hey guys I Am getting a code 81 on my 4520. Can someone tell me what it is? Thank you.

it is invalid or incomplete engine speed data on CAN bus. Do you have a service manual? There are a couple things to check. I can copy some pages for you tomorrow if you want. My service manual is for my 4720, but those parts should be pretty identical. What year is yours? Just wondering if it’s 2009 or newer to have the fully electronically governed engine.
 
   / CODE 81
  • Thread Starter
#3  
Arlen thanks for responding. I found the issue to be a loose throttle sensor connection.

Now I am having problems with fuel shut off control. It will turn over at full speed but will not fire. If I push in on the key switch it will start immediately and shut off when I release the heater contacts. If I hold the key in with the glow plug relay removed from socket it will start too. As long as I hold the aux contracts in for heat the tractor will continue to run even after I remove all the relays.

I have ordered a new manual from Deere, but it will be at least two weeks before it arrives. I suspect it is a latching or holding circuit to keep the fuel flowing to the injectors but don't know for sure. This is a 2009 model with the higher 60 hp engine. All my connections are clean and in good shape. MINE IS THE ELECTRONIC CONTROLLED ENGINE.

Any one have any ideas? I really would like to finish a small job and plant some grass this weekend,
 
   / CODE 81 #5  
Welcome to TBN

You might try sending a personal message to jenkinsph to alert him to your question.
 
   / CODE 81 #6  
I have an older John Deere 4320/ 2006. In order to set my engine speed I had to log into the ECU thru the dash and adjust the engine speed/ rheostat according to voltage shown on the display/ dash. I think it was like .5 to .7 volts. You have a newer version of the tractor. My tractor is a Tier 2 engine. I don't know if this will help you.
 

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