1988 bonneville check engine light

How do i get the check engine light to blink the code. I dont have an obd1 reader. Just it keeps coming on randomly after i drive for like 5 minutes.

this site will show you how to retrieve the codes and has a list of possible codes for your year bonneville

http://autorepair.about.com/library/ts/obd-i/bl-dtcs-42.htm