slc
10-07-2005, 11:32
I changed the rear axle ratio and tires on my 1998 Blazer and now the speedometer is reading fast. I went from a 3:08 to a 3:42 and a P205/75R15 to a P225/75R15. The dealer said they can't recalibrate the ECM to correct the error. I tried four local dealers and got the same answer. Apparently GM frowns upon installing different gears or tires. Does anyone have any suggestions on how to make the speedometer register the correct speed. I know some performance programers that have the capability, but I don't realy want to go that route because of cost.