Deere 450J transmission derated

[Canadian_digger]

My dozer started acting up. It would only go to 2.0 speed and engine rpm would not come up. I shut it down and it would go back to normal. I pulled the codes from the Transmission control unit. I cleared them but now the screen shows !CAL.

Dozer has 4600hrs

I called the dealer and they weren’t much help. Basically said to just bring it in. I would like to know what the problem is before I start throwing money at them.

TCU codes were
F3x1. Trans derated no forward or reverse.

F393. Engine stalled easier under load.

F3H4 no Forward or reverse

 

[Canadian_digger]

Anyone?
Is this a speed sensor issue? Or just needs to be calibrated? Or both?

 

[TNB]

Anyone?
Is this a speed sensor issue? Or just needs to be calibrated? Or both?

Well it definitely needs to be calibrated now so you should probably block it up and try to calibrate and report back with any DTC’s when/ if it fails calibration..

 

[Ronsii]

I worked on my buddies 450J and your computer has way more corrosion showing!!! His was starting to give various codes and what not... sometimes you could let it sit and it would work.... The cause I found was corrosion had penetrated the rubber gaskets around the main harness connector inside the computer. I tried to give it a quick electronics cleaning but it didn't help it and I believe he said it was a 2K or 5K computer... something like that... so I wasn't going any deeper on it He found some place that does flat rate repair on heavy equipment CPU's and sent it off to them to fix for 5-6 hundred I think??? anyways he get it back - installs it and voila... no difference I checked it out again and they hadn't done any more to it the I did but they were charging him $$$$

The main issue I had with fixing it would have been removing the big harness pin header plug as it was three layers tall and if I remember right the pcb is 6 layers so a little over my comfort level for desoldering(without damage) at least for the equipment I have to repair with... basically the corrosion is causing shorting under the plastic spacers for the 90 degree pinheaders from the connector.

In the end he did go to deere and pay the 3 or 5k for a new computer and that took care of it.

And actually the initial failure was from the powdercoating on the aluminum computer housing was letting corrosion between the powdercoat and the metal thereby bypassing the rubber seal. If you open the computer it should be visually obvious and who knows maybe the corrosion on yours will be accessible to clean off the board...and you'll be back in business.

 

[Ronsii]

Found some of the pics.

 

[Ronsii]

 

[mg2361]

Unfortunately C-digger, I have to agree with Ronsii on this one. If the display just randomly changed to !CAL, then something is going on inside the TCU. I have seen many of those controllers with corrosion issues like Ronsii said and yours looks pretty bad. You can block it up and try a calibration, but I think it will be all for naught.

 

[Ronsii]

The funny part was my buddy had taken it to the dealer about a month before I saw it... they scanned it threw a couple parts at it(throttle sensor and a IP sensor) and said it was good so when it started throwing trans codes and not being able to move he called me to go look at it on a job two hours away - I chased ghosts til' mignight on that one... finally got it to move and he threw it on the trailer and brought it home. Wasn't until the next day I started figuring there was too much going on to be sensors or wiring issues that's when I pulled the cpu and opened it up to find the actual problem.

 

[Canadian_digger]

Thank you for the replies. Now I’m getting somewhere. I didn’t realize the computer was asking for calibration. How do you do a calibration?

 

[Canadian_digger]

Got my Dozer calibrated! No
Codes as of now. We will see what happens once I start working it again. Fingers crossed. Thanks for all the help. And A big thanks to MG for sending me calibration procedures.