I need some help! I have a race on Saturday and I can't get my jeep to shift right in 4 low. It works perfectly in 2 or 4 hi. The VSS is in the tailshaft of the NP205. I have a 2007 LQ4 that came out of a 4x4. I have changed the ratio from 2.72:1 to 1.96:1 for the NP205. I have wire 1694 wired through a grounded switch to tell the PCM it is in 4-low. I put the VSS in the tailshaft of the TC because this where GM put it.
Here is what it is doing. It shifts at 1/2 the RPM it is programmed for. It shifts good and hard, etc, just short shifts.
Other facts to note: I have a separate tune for running in 4-low because I don't want to use 1st gear. It is too low and wastes time. Much quicker to start in 2nd. I did this by zeroing all of the shift tables for 1st-2nd shift. Seems to work fine.
As a work around I have told the PCM it has an 80 tooth VSS ring and it works fantastic in 4-low. I know this is telling me something, I am not sure what??? I think it means the PCM isn't calculating the ratio change. I have read that 1694 is for nothing more than the light on the dash. True or no?
jeepwith4l60esegswapRevS.hpt