I'll ask here and post on my thead in automatic transmissions concerning a 4l80e overheating issue on a friends built truck. Has anyone had an issue with a 4l80e conversion harness causing an overheating issue due to ISS/VSS signal problems?

Found out that my buddy is using a PCM of NC 4l60e to 4l80e conversion harness. Apparently it doesn't use the front ISS signal and then some parameters in the trans have to be tuned out? Was wondering if this might be presenting as some sort of slip issue to the ecm/tcm and causing the excessive heat?

I used the Speartech and it does use the ISS since the 4l60e had it internally.

Thanks

 

Did you change the 1,2,3 and 4 gear ratios in the calibration to match the actual ratios the 4L80 uses or are they still set to the 4L60 ratios?

 

I will pass this on. I'm not the tuner but tuner is very competent so hopefully not been overlooked. Thanks for the insight.