I swapped to a 4.10 rear last weekend. Well, I got my new program from Bryan (PCMForLess), loaded it up, and everything seems to work fine, sept the speedo is reading way high. My ACTUAL speed seems to be about 65% of what my speedo shows at all speeds.

1st Bryan sent me a few different programs to try, to see if maybe one was corrupt, and eventually he even rewrote one with everything scaled down to 65% in hopes of just doing a custom calibration instead of using the correct PCM calculations for a 4.10 rear.

Even that didn't work. My actual still seemed to be roughly 65% of my speedo display. Before the rear end swap, I had never had calibration issues, even after numerous reprogrammings.

Well, he finally decided to start from scratch, and rewrite a whole program. He did and sent it to me. During the flash, my ****ty laptops disk drive took a ****, there was a disk read error, the program exited, and thus the PCM was fubared. It was only about half way through the programming so I can't even begin to program it again till I send it away to get repaired...

In the meantime, I bought one off a kid at cz28.com, and it's being shipped to me. Yesderday, a local F-buddy let me borrow his spare PCM so that I could use my car until the one I bought arrives next week. I flashed the brand new, written from scratch program onto the pcm, and everything seems to be cool, except the speedo is still ***ed up...

Does anyone have even the slightest idea of what might be going on or how I can recalibrate it correctly?

 

ttt...

anyone?

 

Does he have the right tranny programmed in, like 6 speed or A4? Double check that with him. Speedo reprogram is pretty straight forward, its got to be something obvious.