I think I got the algorithm and it is as an Excel formula:
=DEC2HEX(BITAND(255;1024+BITLSHIFT(BITAND(2*(BITAND(BITRSHIFT(A1;4);32771)+BITRSHIFT(A1;12));7)+5;4)-BITXOR(BITRSHIFT(A1;8);BITAND(A1;255)));2)
whereby the rate (in dec) is in the excel field "A1" (see also attached Excel file)
So the checksum for a rate of 2472 (=2548 - 3%) should be 0xEF ... maybe someone knowledgable could confirm this?
TD5SpeedometerAdjustmentChecksumCalc.xlsx
No, it's a 130 and I checked with a calibrated GPS and the speedometer shows slightly less than the GPS, which is illegal. So I have to do the adjustment
Hi,
I want to adjust my KPH to +3% to change the tires from 7.5R16 to 255/85R16
So currently I should have a RATE=0x09F4 and Checksum:B3
the +3% would mean I have to reduce the rate to d2472 or 0x09A8, correct?
I read through all of this thread, but in all honesty I don't get the algorithm you were talking about. So what would be the correct checksum for a rate of 0x9A8?
thx, Franz