Should have mentioned in response to your original question re PCM pin out - When I was chasing grounds on the 5V reference circuit for the TPS and the gas gauge, I had very good luck using the schematics available for free on the AutoZone web site. They maintain a huge searchable database of technical documentation searchable by vehicle/model year. You have to register on the site to access the stuff, but there is no charge to register. Once you register you can set up your default vehicle(s) that you will be looking up info for.
