Land Rover Repair: Transmission ECU 00 Diso II, transmission gearbox, error indicators

Question
Yesterday shortly after starting the vehicle and putting it in Drive, The S and M dash lights starting blinking as well as the D lights at the shifter.  I returned home (3 miles) and parked.  The Check Engine light also went on.  The owners guide stated there is a problem with the transmission gearbox ECU with these error indicators.  What are the odds that is true.  Could it be the transmission.  I would like to do the work myself if it's the ECU and I priced it at $200.  Is this difficult for a mechanically inclined person to do?  Any special instructions.  Thanks

Answer
The problem may be the ECU, or it could be inside the transmission or even in the control cable.  Without a Autologic or T4 test system you are just guessing.

If you want to throw in a ECU and see what happens, fine, but if I were you I would find a shop with one of those tools and test it.