That is way to early on the shift points.
You say the cable is all the way out . Do you mean pulled away from the pump (outer part of the cable ).
Can you see where it hooks to the pump, is that on and moves free??
have you tried to adjust it will it go out any more ??
do the shift points raise when you step down on the pedal ?
2017 L5p Slt c/c s/b
2015 Enclave premium package wife's ride
1998 Chevy K-1500 Z-71 X/cab. 410 k
2016 Canam commander 1000xp
2015 Slt c/c s/b (traded)
2004.5 Gmc c/c s/b LLY sold