- 2004–2009 Factory-verified
Also described as Transfer case, electric shift control, two speedTransfer case, two speed, electric shiftTransfer case, electric shift, 2-speedTransfer case, electric shift control, 2 speed
Also documented for CadillacChevroletOldsmobile
Documented applications
- 1998–2001 Factory-verified
1999 list reads selectable shift, push button control
- 1998–2000 Factory-verified
- 2000–2007 Factory-verified
2005–2007: heavy-duty models only (GM’s HD list)
- 2001–2007 Factory-verified
- 2007–2008 Disputed
printed in the 2007–2008 lists only; the 2009 list prints NQF disputed: the 2007 and 2008 new-body Sierra lists print it in the heavy-duty half, but that half repeats the 2007 Sierra Classic heavy-duty list (same codes, same order) and no other source names the GMT900 HD gearboxes, so it may be a Classic carryover; both readings kept
- 1998–2004 Factory-verified
1999 list reads selectable shift, push button control. The 2002–2004 lists read as the 2001 list.
- 1998–1999 Factory-verified
- 1998–1999 Factory-verified
- 2000–2002 Factory-verified
the 2000 list words it as a full-range transfer case
This page aggregates every documented appearance of NP1 in the GMC reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.