Auto box td5 m & s lights flashing

have no power and the M and S lights flash togrther, put it in 4 wheel drive and drove 1\2 mile, tuened vehicle of back in high mode and was all ok no lights flasing, got in this morning lights back on and flashing
any advice please

The M & S light flashing means that it has gone into limp home mode and is will be stuck in third gear. The usual reason is that the XYZ sensor needs to be replaced.

Also the Discovery is permanent 4 wheel drive. I think you probably meant you put it into low range. No need to do that, just restarting will reset it.

First and most common reason for flashing M & S lights is a weak battery. The EAT (automatic transmission electronic control) is very sensitive to battery voltage.

How old is your battery?