Read Code On 88 K1500 HELP

[Fowlkes57]

I did the paper clip trick with my trick since its OBDI not OBDII, and when i did it, it blinked once, paused then blinked twice.
Which is 12, I beleive. But the websites ive been to say there isnt 12 code, and it starts at 13. Im hopelessly confused and any help would be great.

 

[Fowlkes57]

It flashes, pause, flash flash, pause pause, and then repeats two more times. and I researched it and it says that it should do that (meaning that its in field service mode) and then the other code should show up, but nothing else shows up. Why is my SES light on if i dont have any codes?

 

[94Sierra4x4]

Unhook your battery for 10-15 minutes and try again

 

[Wstrnsky]

Yep unhook battery should reset the ses.