After I changed from the 4l60e to a Coan 4l80e the speedometer runs 1/2 speed.

What do I do to fix it?

Thanks, Jim

 

I think you may have your input speed sensor and your output speed sensor reversed. The 60 had an output only. The 80e has an input and an output sensor.

 

Segment swap or relay setup to control the trans?

 

Segment swap. HP didn't have a program to wed the 5.3 and the 4l80e so Dusty Wilde found someone to do the segment swap using EFI live and then have that put into language that HP tuners could use.... as I understand it, and I understand NOTHING!

 

Did you do the swap or did somebody else?

I would check the ISS and OSS sensor connectors.

 

I did not do the swap. A professional shop did it, but they were not familiar with the swap. Thanks for the idea. I'll pass it along to them.

 

i wanna say the rear OSS wires are green purple? ISS wires should be red blue?

 

If the the speed sensor wires were swapped then your speedo should be turning with the vehicle sitting still in park or neutral close to engine RPM. I don't think this is your issue. I would look to see what the pulse count is in your tune. It seems to me that the manual program is close to 1/2 the pulses to an auto one.

 

Thank you Vince. I'll be getting a tune shortly and I'll ask them to check on what you've mentioned.

I had wondered if there might be something in there that would/could affect this as there was a lot of confusing surrounding the tune after the trans was installed.

Since HP didn't have a program that would work with the 5.3/4l80e combination there were several segment swaps attempted prior to Dusty getting something done that would work for the engine and trans. Prior to that getting accomplished there were several attempts where the engine would run fine but the trans wouldn't shift out of 2nd gear or the trans would work fine and the engine would barely run. The final segment swap and then the conversion from EFI Live to HP, it seems to me, could have easily left the computer with a manual trans signal to the speedo. That makes a lot of sense to me, given all the confusion.