Originally Posted by
onehundred80
I think the communications plate is sometimes called the electrical plate or the Electrical Control Unit. Here it is shown bolted to the hydraulic unit. Together they make up the Electrohydraulic Module.
The ECU is the plastic plate and solenoid covers etc on top of the aluminum hydraulic unit. The leaky electrical plug socket is shown in the bottom right hand corner of the picture.
What goes wrong often is a solenoid valve, by default the unit should select only second gear and that is called 'Limp Mode'. I have had it and driving speed is restricted as well, it makes for a slow ride home.
If it is a warranty repair the dealer will likely replace the faulty item, if it is a customer pay job then a whole new unit is fitted. On mine they rebuilt a solenoid.
The OP's problem probably lies here in the speed control.
So where is this located and how much do they cost?