Did a search but was unable to find any threads with this problem. With ignition key off i jumped the A & B connector pins on the data link connector with a paper clip. Then turning the key to the on but not start position. expected to see the ses light flash the trouble codes, but didn't. It just stayed on steady. Made absolutely sure pins were jumped correctly and that pins were clean. tried again, this time with key on, not in start position, jumped a & B pin still no flashing ses light, just stayed steady. Could possibly be bad ECM or other problem. SES light occasionally comes on intermitantly while driving, so i need to get stored codes to fix problem and clear them. Any ideas?

1988 5.7L tpi, auto trans. stock