help begginer

hi i just brought a p38 2.5 bmw TD and soon as i select a gear the computer tells me to select neutral and then drive over 40mph and select neutral it tells me to slow down whats going on ? it at the correct ride height and not in low box
help
thanks

Manual or Auto???

What it is saying by displaying the Select Neutral message is that it thinks you have selected a ratio change from low to high or vice versa and you shoukld select main gearbox neutral and wait for the ratio selection to change before going into gear.

The speed message is there because the Transfer Box ECU thinks it is in low range and you should slow down.....

I would think this is caused by one (or both) of two things.....the transfer selection motor is duff (it has position switches in it to tell the system which ratio it is in) or the transfer case ECU is playing up....

Get it on diagnostics and see if any fault codes are shown - my bet is on motor and/or ecu