Hey all. So my super-clean 2012 Colorado LT 2WD Z85 ext cab will not crank, fuel pump will not prime, stab sys service, traction fault, low fuel ( has at least 5 gallons), starter works (jumped), NO passlock light, no shift indicator light, battery load tested good, ground packs redone, terminals done, all connectors (I can see) fretting procedure done, interior and carpet taken out ( 3rd brake light leaked), PCM and BCM sent to G7 tested good, FSCM connection cleaned (not metered yet, need diagram), scan tool (simple Actron) "no link" even with sensors disconnected one at a time. Aftermarket radio (out of dash now) with metra module, was fine for four months prior. Split the fuse panel, cleaned and reinstalled. Replaced ignition switch and housing, tried PCM replacement. I'm going out of my skull with it. I was thinking FSCM (FPDM), but after weeks on various forums, I have not seen one cause a no crank. BTW I've bench tested all the relays in the fuse box. The neutral safety switch is not where it is shown on all the part diagrams I have seen, on the shift actuator drivers side of trans. I've inspected every inch of harness underneath. I have fixed every vehicle I've ever owned for 36 years of my life, and this simple truck is the worst electronic nightmare ever. I am hoping it is some stupid step I missed, any direction would be appreciated.

 

Sounds like you covered a whole lot already, I'm impressed. Your scan tool won't communicate, is that correct?

 

It's a combo switch on side of trans?neutral safety,gear selector for pcm and reverse lights?

 

Scanner has power but "no link" message. The NSS doesn't exist where it usually is, not on the trans driver's side at shift input lever

 

It's not there and no wires in the split loom harness for it.

 

Head scratcher?now you got me looking

 

Found, sometimes called,shift position sensing unit,but no location,also on eBay,acdelco#89048415 showed up?

 

Bad info all over the internet,yikes,I now understand,I'll keep searching

 

Ok,with that #, another shows d2260c, safety start/warning switch?saw your thread elsewhere too,holy cow,sorry for the problems your having,I even went on Holden sites in Australia

 

So I went to the Chevrolet dealer and for my VIN the switching is inside the transmission. Lucky me. Either off to the dealer service center, or try a new TCM, it accepts the info and sends it to the instrument cluster and the PCM if I'm reading correctly? Thanks to all who have been looking around for me.