Cadillac Repair Questions? Ask a Mechanic for Answers ASAP
Does it crank at normal speed?
Do you have some ether or starter fluid, and spray some into the throttle body to see if it will start?
How many miles on this engine now?
I was worried when you said sounds like no compression.
Can we get another scan done now, it may have a new code.
Do you have any fuel for a 4 stroke mower handy?
A spray of that would do, you'll know if it has a partial "cough" into life.
What was wrong with the original PCM, and who fitted the new one?
If you take the duct off at the throttle body and spray some fuel in there, don't need much.
Slip the duct back on, and crank it up.
If it has anything different from a "cough", to start and run for a second or so, then we know the engine mechanical and spark is fine.
It could then be a fuel pump.
Do you still need help?
I hope my advice has been of assistance to you.