For verification:
1) Check the dispersion on the frame which must not be greater than 30V
2) perform reversing 2 IN-MOTION to see if the problem is on power
3) Check the bearing rotor (14162-F2130-71) that sends the right signal to the CPU
Regards - Franco

Make by your one test lead and test with scope you will see the problem with one channel
Its A problem in the Cpl range off toyota where the encoder bearings mounted
And go with the number off bearing to A Bearing shop they have the bearings to and the cost off the bearing is many lower than its coming off toyota.
Externally is not possible with this truck

Regards

John.

the encoder bearings are a common failure item. if you can devise a way to install a 2 channel speed sensor externally i would definately like to see it and use it.

Thanks, I will check the signal with a scope.
On this machine there is one drive for the pump and one for the two motors so i can not swap it.
I have a answer also from a toyota technician and the problem with these machines is that the magnetic field in the motor can cause that the (internal) encoder fails.
The solution would be to build a external encoder.

the speed sensor can be checked on the display but not always accurate. it can be checked with a meter that can read frequency. connect to negative and test the brown wire and the black wire with a white stripe (backprobe) and run machine. they should read relatively evenly. if one chanel is failing the controller can not sense direction of rotation immediately and may cause the problem you are having. if you need instructions on using on board diagnostics let me know and i will help you through it but for this test the on board is not very good. if i may i would like to ask you something, are the two motor controllers interchangeable on this unit. they are on ours and it is a good diagnostic tool.