Have you considered buying a service manual set? It has happy things like pinouts and component locations. I got my for ~$250, 3-4 years ago. It's been invaluable. I got the three-volume, ~2000 page purple set that covers all '07s from eBay. Helm may have original sets in stock, but the last time I checked, they had been out for quite awhile.
In the mean time, you should be able to test the P/N switch without pulling anything apart. The switch connects to the harness (duh) so you should be able to probe the other end - at the ECM or BCM (or transmission controller, if this car has one) - and check for continuity when the car is in park and in drive. I'd try that before tearing into the transmission.
Alternatively, if you're limber, test it at the connector on the transmission while having a helper shift the car.
I haven't tried this as I have a five-speed, but it's essentially what you'll have to do after dropping the pan anyway, without having to drop said pan. After breakfast, I'll pull the manuals out and see if I can find some pinouts and maybe a diagnostic procedure in the FSM.
Blue-ish 2006 2.4, Werks stage 1 turbo, Borla cat-back, DDM braces, Spec aluminum flywheel, Spec stage 2 clutch, Werks aluminum radiator, some gauges, RKSport hood, Morimoto FX-Rs, GReddy Profec, Norm's fenders
'07 GXP, RPM Stage 2, Solocatless downpipe, TCE Wilwood 6 piston front brakes, 4-piston rears , Stainless brake lines, slotted/drilled rotors, BC Racing BR coilovers, Performance Autowerks intercooler, DDMWorks CAI, charge pipes and braces
Last edited by raygun; 01-07-2019 at 07:09 AM.