Join Date: Nov 2003
bob2231 is offline
Re: How to look up Service Engine Soon codes without scan tool
One thing that maybe everyone knows,but in case anyone is doing this for the 1st time.When you jump the terminals and turn on the key,the light will flash 12 twice in a row to confirm that you're in diag. mode.
After that any codes that are set will flash twice in a row,gives you time to write them down.
Clearing them without a reader is also easy.Disconnect both battery cables for a min. of 30 seconds,I've also been told 60(my '92 Eldorado said to hold the 2 cable ends together,don't know if that's required for the Blazer but I do it anyway).
Hope that helps.