Please HELP !!!

Today as I was just pulling up outside my house the car started to smell a little and the warning light came on don't know if any power problems.

Called the AA ( What a waste of time ) the AA Guy would not tow it he made me drive it to garage Halfords Auto centre.

On driving there NO Smell & NO Warning light speed of about 30 - 40 MPH
It is showing no fault codes but think the Autobox has it's own ECU Box be told crazy prices to get it plugged into read the ECU but an Autobox Centre where I also took it to said it drives ok and it might not show any thing..

What would you do I need the car as mrs goes in for OP this week and need the car bad ... Thanks