automatic locks???

Thanks again LMP and Tim1400 for the info on the service engine light. One more question... When i first got my 98 trans sport it used to lock all the doors when i put it in gear and now it dosen't. and for some time now the passenger side sliding door does not lock or unlock with the keyless entry. Anything i can do to fix either of these problems??? The sliding door incident happend months before the locking when putting into gear did. Any solutions or hints would be greatly appreacated. Thanks in advance.

There were some hints on similar subject lately and good advise was to train the key all the way back and forth- lock and unlock - several times on all door locks..may be use some lubricant at same time. Correct positioning of mechanism may be the solution.