po721

[HLBLY DLUX]

2001 LB7 with Allison
k&n Cold Air Intake 4 inch waste pipe
2805 Flashpaq tuner
8 inch lift, 35 inch tires

what would be making my trannie go into limp mode
with or with out the flashpaq

getting code po721

[ynotracing2221]

Sounds like your clutchs are toast if it keeps on going into limp mode even without a tune. Time to build your tranny! Thats just my .02. Maybe Mike L will chime in and give you some other info.

[Mike L.]

Originally Posted by ynotracing2221

Sounds like your clutchs are toast if it keeps on going into limp mode even without a tune. Time to build your tranny! Thats just my .02. Maybe Mike L will chime in and give you some other info.

Output Speed Sensor.

You may have a wiring problem at the speed sensor ( in the transfer case on a 4X4, in extension housing in a 4X2 ) or bad speed sensor. Problem could also be in the exciter wheel in the trnafer case.

[HLBLY DLUX]

will having 35 inch tires make this happen and correcting the speed in any way

[Mike L.]

Originally Posted by HLBLY DLUX

will having 35 inch tires make this happen and correcting the speed in any way

Tires will make no difference. You have a problem with speed sensor.

[HLBLY DLUX]

thank you the abs light is on as well now that is connected to the speed sensor in some way