It could be the steering wheel rotation sensor needs replacing. That's what was wrong with mine. It was done by the dealer so I have no idea how to do it.
Check www.autozone.com, they have a Repair Info section that covers Buick LeSabre with this info.
To repair a seat heater on a 2004 Buick LeSabre, disconnect the connector and check for voltage. If there is no voltage, replace the switch. If there is voltage, check for an open circuit.
1997, 98 and 99 lesabres are supposed to bigger inside so check with a dealer or wrecking yard.
Check for a vacuum leak.
check your manuel
Owner's manual.
I have a shimmy or small vibration while driving the interstate on my 1994 buick lesabre - if i was to check the front and rear bearings - how would i do that and what would i look for
Check battery and cables
Probably 4-5 quarts check after 4
check under car at the passenger rear door .
installdr.com
Get a code read out from your engine computer and it will tell you what is wrong.