I have a customer with a 5.3L and a 6L80E in his 2009 truck
I’m running into an issue with calibrating his speedometer.
im using EFI Live.
35” tall tires. 4.56 gear ratio.
I wanted to adjust his shift points and correct the error. But for the life of me, I can’t seem to get the speedo to change what it’s reading.
EFI Live has a speedo calculator in the tables for both the E38 and the T43 I’ve made the tables match using the calculator Flashed both the ECU and TCM No luck! I’m still 6mph off at 60
Any help would be appreciated! Thank you!