i have a '94 GM .the SES is on .
and i dont know how to read the codes. it has a 12 pin connector under the dash.
tried shorting the A to b terminals together. but the B terminal is missing in the plug. so nothing happens. it appears that there is 3 wires in the plug. on terminals A,M,J.

___T___
XXX XXA
XXJ XXm

what i would like to find is a low cost scanner to read the codes. but from my research with out the B terminal the low cost obd-1 scanners wont work .an it would take a tech 1 scanner to read them.
is this correct?

i recently put together a serial cable an winaldl to scan an older s10 pickup .an i was wondering if there were any programs like this that would work.

this is a ECM 16196401 is this 160 or 8192 baud on the m termial.

anybody got any ideas! thanks rob