Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
That error means that the incline's position has exceeded tolerances. You (or a tech) should recalibrate it.
To recalibrate the incline, turn the machine On with the safety key inserted already.
***Do not have anybody standing on the treadmill, throughout this it should be clear!***
You should see model # ***** and units.
Set to the correct model # (9600 I would think) using the Elevation arrows,
and set to the correct units (0 for miles, 1 for km.s) using the Speed arrows.
Then press and hold down ENTER.
Then press START also. That starts calibration.
Treadmill runs and does things for about 5 minutes, then displays "END".
Then the treadmill will reboot and go back to a starting screen/display.
That's the procedure, I hope it helps. Let me know whether it clears the error - or not.