Land Rover Repair: To clear Check Engine light, key fobs, vacuum problem

Question
Hello John, I have a problem with my 1995 Discovery I 3.9 Gasoline v8.
The check engine light is on and according to the display under the passenger seat I have a problem with the stepper motor, code 48.
Now,I have some instructions on how to clear the Code without disconecting the battery, would disconecting the battery damage the computer at all?
Anyway,this is what I have: first step to clear the code is to Switch the Ignition on.Second, disconect serial mating plug,wait 5 seconds,reconect.
Third, switch ignition off and wait for main relay to drop out.
And fourth, switch ignition on and code should be cleared.
My question is: "where is the serial mating plug?".  
Please help, thank you.

                               Abraham  

Answer
Hi Abraham,

there is a serial port located under the steering column.  This is often used to reprogram the ECU, key fobs and security system.

Disconnecting the negative cable from your battery does not damage your vehicle, if its done properly.   You can remove the cable for 20 seconds and then reattach.  You'll have reenter the security code for your radio and reset the time.  

That codes sometimes indicates idle problems...could be a vacuum problem.  Do you notice any idlng problems?  I sometimes get code 45 (oxygen sensor) but it goes away.  My idle is fine so far (knock on wood).  

I've never done the procedure you mentioned, although it sounds very much like the ECU reprogramming combined with a security procedure to reprogram key fobs.  

Best of luck with this,

JohnMc