I need some guidance on a JD 650J. Serial number: T0650JX146972. I cannot scroll through the codes on the TCU. Only code is F311 but I know it has more. Is there any troubleshooting that I can do to test the TCU? I’ve checked all harnesses and connectors. Can’t find any broken wires or corrosion. Thanks
So your "NEXT" button is not working? That alone may require a TCU replacement. What you need to do first is pick an easy transmission sensor to get to, back probe the "A" terminal wire and measure the voltage (that code sets when the voltage is below 4.8 volts). Report that voltage here. Then unplug that sensor while still backprobed and see if the voltage changes. Leave the meter connected to that same terminal, then unplug every transmission sensor, one at a time, while observing the voltage. If the voltage rises when a sensor is unplugged, then you have found your source of your code. If the voltage never rises then there is either a short to ground in one of the sensor wires, or your TCU sh** the bed. Check your messages.
It was indeed the TCU. I replaced the TCU and now I can’t calibrate….. I’m sorry to keep bothering you on this. But do you have the calibration steps? It won’t even get past the DecelB part of it
Your decel may be adjusted incorrectly. Check your messages for the calibration procedure.
I’m struggling with this calibration on this TCU. Bought a new TCU and now I can’t get the calibration past the DecelB part of it. I adjusted the sensor and still nothing. I still have active codes F372, F382, F3B8 and F3U4. From what I can find non of those have anything to do with the decal pedal. Help is much appreciated
What is the machine's serial number? I want to be sure you have the correct calibration procedure and specifications since there are several for the "J" series. When pressing the pedal down, are you stopping when you feel resistance, or are you pressing down against the spring until the pedal is all the way to the bottom? The F372 and F382 might also prevent you from completing the calibration. We will worry about that later.
T0650JX146972 I’m pressing to the detent.
The procedure you have is correct. Make sure you push through the detent until the pedal cannot go any further.
Through the brake as well??
We are dealing with the decel pedal, not the brake pedal, if you are not getting past the throttle portion of the calibration. The decel pedal has a spring loaded stop. When you reach the resistance of the spring, continue pressing until the decel is all the way to the bottom against the physical hard stop on that first part of the calibration.