I have a 1994 Silverado Extended Cab 1/2 Ton Truck 5.7 liter V8, with Check Engine Light coming on after it warms up. The code I get when I short terminal AB is: 12, 12, 12, 3, 2, 3, 2. Then it starts again: Long dash, short dash, short dash; Long dash, short dash, short dash; Long dash, short dash, short dash; short dash, short dash, short dash; short dash, short dash; Short dash, short dash, short dash; Short dash, short dash.

What would you say is my code number(s) to look for? I appreciate any help you can give me.
Thanks,
Fritz