2006 4.3 5spd Sierra can't connect

[Ritch]

I'm using V1

also I tried 7 and 7.5 software versions.

When everything is plugged in and I try to read PCM calibrations, the lights flicker on my FlashScan FSP V1.2 but EFI acts like its not plugged into the truck. I am selecting the GenIII PCM type. Can't think of what else to try

[ScarabEpic22]

Make sure its the Gen III 99-07 (or 99+, cant remember) and not the 97-98. Probably already doing that but it never hurts to start at the basics. Anything aftermarket on the truck, like an alarm or headunit? Sometimes have to pull the fuses for these things, and Onstar sometimes.

[Ritch]

Yah, its got a different radio and a government installed breathalizer.
Next time I see the customer I'll have to check for power at the plug. Anybody know which terminal should have 12vdc?

[ScarabEpic22]

No idea, I think all OBDII have to have power to the same pin. And I mean pull the fuse for the radio so it cant interfere with the VPW bus as you are trying to read it.

[GMPX]

I'm using V1

also I tried 7 and 7.5 software versions.

When everything is plugged in and I try to read PCM calibrations, the lights flicker on my FlashScan FSP V1.2 but EFI acts like its not plugged into the truck. I am selecting the GenIII PCM type. Can't think of what else to try

Can you at least get the VIN or anything?
2006 might not be using the old GenIII PCM.

Cheers,
Ross

[Ritch]

VIN#3GTEC14X96G229310

This number is off the dash. There was no communica with the PCM

[Lennart]

The OS should be: 12606807

[Ritch]

OK so the Cig lighter is on the same fuse as the OBD port