Not sure if the PCM uses the shift switch on the side of the trans to allow the trans to shift out of first gear automatically. It could be a possibility though. I retained my selector switch not kinowing if it would work without it.
Another possibility, although remote, is that the VSS is defective or the harness to the VSS could be at fault.
I had a similar problem with my swap when I first started to drive it, no upshift from 1st to 2nd. Turned out I wired the VSS to the PCM and the DRAC box to allow the speedo to work. After removing the wires to the DRAC box and leaving the PCM wires on the VSS, the trans shifted perfectly.
Last edited by Mickeymotormount; 10-13-2013 at 06:58 PM.
'93 Chevy 1500 4X4 ECLB with a '99 Silverado LQ4 6.0 and '99 Escalade 4L60E. SOLD IT!!
New toy: 2001 2500 HD 4X4 Extended Cab Long Bed
John
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