TN75DA Transmission Code 41 ECM Troubleshooting

   / TN75DA Transmission Code 41 ECM Troubleshooting #1  

djkelly53

New member
Joined
May 10, 2013
Messages
4
Location
holly, mi
Tractor
New Holland TN75DA
Hi,

Long time reader, first time poster... I have a 2006 TN75DA that is setting a Code 41 now. Read below after my timeline for what Code 41 is in case you have it also. I have had the following conditions happen so far in trying to figure this out:

1. I drove my tractor in reverse out of my garage using the clutch, putting shuttle shifter in reverse then letting up on the clutch pedal to move. I went 50 feet (maybe).

2. I shifted the shuttle shifter forward to change direction to move forward and nothing happened. This is the first time I had even seen any kind of code, ever, in my tractor. I waited a while to figure out which code was trying to be communicated: fast flashes + 4 + 1 for Code 41. This is set with the redbook+small gear. I found I can get this to set without the tractor even running also. Just keyed up and pressing the clutch pedal and moving the shuttle shifter forward and letting up on the clutch makes the code set.

3. Some of you might be thinking at this time to tell me that I shouldn't have to use the clutch in the beginning of driving the tractor. -I know that. I read through these forums that it could be as simple as the seat switch, so I checked. Sure enough the seat switch wires were cut clean... my theory is because I had adjusted the spring rate of the seat when i first bought this tractor so the seat would have more spring and after a few good bumps the seat came down and cut the wires. The shuttle shifter convenience of just moving it forward was lost after the first few months of me owning it and I called a dealership to explain the new way of operating it with the clutch and the one i bought it from thought that using the pedal is how it is done. I stripped the red and black wires for the harness going to the seat and twisted the wires together to bypass the seat connector (this is temporary, unless it works :D)

4. Next I read on this site that if I swap connections of the Forward Solenoid and the Reverse Solenoid I can pin point where the problem is... Well, I did that. I could drive forward after swapping the Forward Solenoid connector to the Reverse Solenoid and vise versa. -HOWEVER, Now I could go forward BUT with the shuttle shifter in reverse, NOT forward! :confused:

5. So at this point I had the connections swapped on the solenoids and I am able to drive forward, with the shuttle shifter in reverse, with the code still flashing at me and I have no reverse whatsoever. After driving my tractor back into my garage, I parked it and started pulling covers off, checking for continuity and resistance of the solenoid. -I have 10 Ohms on the forward solenoid, but it works regardless because I am able to drive it.

Questions for this code 41: What does this mean that I can swap solenoid connections and still move, but with the Shifter in reverse? Does it point to the harness, needing a new Shuttle Shifter or does the ECM need to be replaced? If its a new Shuttle Shifter, what is the part number?

Does anyone live near the Flint, MI area have a TN65,70 or 75 that I can put my ECM in to test its functionality? I am going to call a dealership also to ask them the same thing.
Or better yet, does anyone near Flint, Michigan own the scan tool that can pin point more than just the electrical tests I am attaching?

Note: I leave a trickle charger on my tractor because of a small draw I have that i need to spend some time to fix. I went on vacation and when i returned I noticed my power had gone out in my house because the clocks were flashing. Is it possible that a electrical surge has been sent through my trickle charger, to the battery, to the ECM in turn frying it? I connect directly to the battery Positive and Negative -Or does the key need to be ON for that to happen?

I found so far a new ECM is $900.00 :eek: and a refurbished one is 675.00 w/ a $100.00 core. I'll be double checking the harness and the shorts to ground to make sure I didn't miss something before I spend that much.
 

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   / TN75DA Transmission Code 41 ECM Troubleshooting
  • Thread Starter
#2  
Update for 10-11-2017, in case anyone is having the same issue in the future and wants to know what I did.

I pinned out the harness using the scanned images I posted to the point of the paperwork telling me to replace the ECM... I called the Flint New Holland dealership and the Service Manager recommended I replace the Shuttle Shifter switch because he had seen a lot more of those fail vs. the ECM. I will hopefully be getting the new switch today to install then I'll post a new update. My theory if the shift lever is bad is that the steering column has no rubber isolation at the mounting bracket, other than a thin piece of cardboard to protect against the circuit board from shorting out, to reduce vibration to the circuit board which probably caused a solder joint crack either on the board or within one of the switches. I'll be adding some small rubber mounts to isolate the new one if it ends up working to so it is better protected against vibration. I might run into grounding issues because I believe the shift lever grounds through the steering column bracket. I'll just try to make sure the screws are well cleaned for the shift lever's mounting threads.

Also, I was told there are 5 different Shuttle Shift Levers for the 2006 TN75DA. My lever is PN 47132542. It is quicker to receive by dealership for 238$ than by Messicks.com for 219$ and I can more locally pick it up. If it fixes nothing, expect to see it on EBAY for the same price I paid for it. Looking at this lever makes me think it is not serviceable whatsoever unless you cut it apart, drill out the rivets and de-solder and re-solder the board's switches. The 870 page manual doesn't pin out the switch for resistance values that I could find. If anyone knows what page those are on, I'll gladly try it.

-While I was pinning everything out, I decided to make a large access hole in my cab so I can reach all of the transmission connections under the parking brake with 2 hands without ever taking my left rear tire off. (It's loaded + heavier than I am + How the **** would I test driving forward with the wheel off safely?). I just need to make a plate to cover up the ~1'x6" hole I made. I basically extended the tiny hole that was already in my cab to the left all the way to the tunnel shape of the cab.
 
   / TN75DA Transmission Code 41 ECM Troubleshooting #3  
I know this is an old thread but did you ever resolve that code 41?
 
   / TN75DA Transmission Code 41 ECM Troubleshooting
  • Thread Starter
#4  
I did get this solved... I pinned out everything according to my shop manual and eventually gave in and had the tractor picked up by my local Flint New Holland Dealer. They performed the same measurements I took then replaced the ECM that I told them to do right away. Bill was about $1,800 with the diagnostics and parts. Core was about $150. A new ECM needs to be programmed for your specific tractor so there's tools I didn't have that I gladly paid someone (dealer) to use for my fix.

I later learned my TSC battery was junk after 2 years as it wouldn't hold a charge. Temporarily I'm using a deep cycle battery because I have a drain somewhere on the tractor still. I know it's not the radio since I removed that completely.

I hope this thread helps someone else's issue for the codes. ECM replacement was the last resort for me. Shuttle shifter replacement did nothing for me so I returned it.
 
   / TN75DA Transmission Code 41 ECM Troubleshooting #5  
ok thanks for the reply glad you got her going!
 
 
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