Hi Radd
You have got some great advise already here. Not sure of the specific issue and or age of your truck, but Combilift have a dedicated Technical Team that are there to help. If you still need support, you can complete a quick technical support form at the bottom of the main combilift.com web site or direct link https://warranty.combilift.net/technical-support-form/. The form only asks for the minimal info so the team can quickly help you. There is no login required and no charge for this support.
Hope you get this resolved
Richard

Sounds like the input from the directional lever is working if the pump motor kicks into higher rpm.

I wouldnt think anything wrong with the steer sensors, relay 9 or the 6 port valve if you can manually steer into side mode as well.

Id be checking the 90 degree mode change solenoid on the electric section of the control valve to see if the coil is okay, connected and that the coil connector has a red light on it when you have selected side mode while in F/R mode.

hi sounds like the gear lever is faulty check any loose wires check replace lever if necessary - check wheel sensors are liluminated check sensors are in the right place not been hit or damaged and also relay number 9 behind the console where your gauges are which can cause that same problem good luck hope this helps im sure richard irwin from combilift can help you further