stangjr
Mon, August 4th, 2025, 02:54 PM
Trying to calibrate my speedo for the new tires and im not sure its doing anything. I adjusted the revs per mile to what the new tires are and my GPS is still showing 4-5 mph higher than speedometer. Original tires revs per mile was 649 i think and my new tires are 579...
Any advice would be much appreciated.
cleatus12r
Wed, January 7th, 2026, 09:50 AM
I know this is a very old post, but the Anti-lock Brake Module controls the speedometer. The Vehicle Speed Sensor's first stop is the ABS module where the AC sine wave from the variable reluctance output is converted to a digital signal read by numerous modules in the vehicle.
Certain scan tools have the ability to reset the revs/mile in the ABS module as the PCM has nothing to do with it.
stangjr
Wed, June 3rd, 2026, 03:46 PM
I know this is a very old post, but the Anti-lock Brake Module controls the speedometer. The Vehicle Speed Sensor's first stop is the ABS module where the AC sine wave from the variable reluctance output is converted to a digital signal read by numerous modules in the vehicle.
Certain scan tools have the ability to reset the revs/mile in the ABS module as the PCM has nothing to do with it.
You were absolutely correct sir.
I got a license for forscan and the OBD2 to USB adapter and boom i was able to correct my speedometer.
cleatus12r
Wed, June 3rd, 2026, 04:03 PM
Nice!
Glad to see you were able to correct the issue!