I swapped engines from a 01 gm b7 170 hp to a 02 gm b7 190 hp with a bad engine and ecm . I tried a 190hp ecm off of a 99 and 2000 runs fine but the speedometer and odometer is wacky. I do not see a speed sensor buffer like the 99 b7 has . I thing the speedometer must be calibrated in the ecm. can the 2000 or 99 ecm be repogrammed to operate the speedometer. or do i reprogram the 2001 170 hp ecm that makes the speedometer work to 190 hp and recalibrate the tire size and gear ratio. would a tech 2 scan tool do the speedometer part .
Tech2 won't do anything but ABS brakes on a GMCV with a CAT. I would check into getting the correct calibration for that engine serial number, CAT should be able to bench flash it from the dead one. Do you have CAT software?
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