How do you find a particular terminal on the PCM?

Trying to fix a misfiring problem on a '95 Lumina APV 3.8L and AutoZone how-to says to check voltage on the RB9 terminal on the PCM. There are three harnesses of wires attached to the PCM. How do I find RB9? Thank you.

With a comprehensive factory based diagram, you could try autozone.com, repair guides for basic diagrams but it may not identify that circuit. What code did they come up with to give this info?

I stopped at a repair shop and their scanner indicated a problem with the camshaft position sensor and/or its circuit. They replaced the sensor but that didn't help. They were too backed up with work to check wires and other parts so I checked to AutoZone's online repair manual where there are basic diagrams. A "630 Blk" wire runs from the ICM to RB9 on the PCM. They say check the voltage at terminal RB9. I'm not a repairman but I could easily check the terminal if I knew which one it was. Does the R in RB9 stand for right? Would it be labeled on the harness or PCM? Thanks.

May be on the connector, what voltage are you looking for and when are you supposed to see this?

It's supposed to be 5 volts, when key is on, engine off. Will remove the connecters this weekend and see what's there.

That is the reference voltage out of the pcm, see if you have it at the sensor end.

Yes, there's approx. 5 volts at A-B of sensor harness, and 12 volts at B-C.

Then you are good at the pcm end, correct?

The '95 231 V-6 (VIN L) cam position sensor (CMP) and the crank position sensor (CKP) are actually connected to the ignition control module, and not directly to the PCM. As a result, the PCM only gets signals conditioned by the ICM. If there is a connection problem, ground problem, or ICM problem, the error code can occur with even a new sensor. Further, the signal can be tested at the ICM, right out on the front of the engine, instead of at the PCM (same wire, different end).

http://www.finemotorcars.org/files/231V6CMPSchematic.jpg

The other possibility is that the sensor target is faulty. It is on the camshaft sprocket, and can become contaminated by metal chips and fines, although a good sensor should be able to read through much of that. The target (magnet) can also fall out of the cam sprocket in rare cases.

In my experience, the connector at the front of the ICM can sometimes be a problem, incurring moisture intrusion, corrosion, and mechanical damage from interference.

Thank you. The connector at the ICM looked free of moisture and corrosion. With key on & engine off, the cam signal out wire at the ICM was about 5 volts. With engine idling for a minute, the voltage varied from 4.5 to 4.95. The next step in the how-to says look for a poor connection at PCM terminal RB9, so I guess I'm back to my original question..where exactly is this terminal?