Service Engine Soon/Temp Light

my 1990 buick century this morning while driving on the highway, the service engine light and the temp light came on at the same time. it felt like the car downshifted and i released the gas, both lights went off... i wont have a chance to get to autozone til the weekend for them to read the code... does anyone have any idea what this could be.. it happend twice within 2miles, but stopped there after.. i drove another 25 miles to work and nothin else happed...the light came on about 20mins into my drive

Maybe it's out of coolant? Your car is obdi. You don't need autozone to read the codes.

how do i read the code then? and no, i checked the coolant when i got to work it was fine. plus the duration of the temp light/service engine light was too fast for it to be overheating, it was on for less the 2 seconds. then both lights shut off.

Try here:

is so much info on the web on obdi that I don't even bother to = bookmark it anymore.