What is the 62 mile bug?
#2
Re: What is the 62 mile bug?
Originally Posted by BigPanda
Saw some posts in regard to this, but haven't been able to google any info on it. Can anyone fill me in?
Thanks,
BP
Thanks,
BP
Many of the HCHs have a bug where the MPG calculation is reset every 62 miles or so, even when the trip odometer itself is not reset. So we cannot correctly track lifetime MPG, or MPG for a tank of gas, or MPG for any trip that is longer than 62 miles.
#5
Re: What is the 62 mile bug?
Originally Posted by dshelman
Interestingly, 62.14 miles is 100 kilometers.
Last edited by toast64; 03-31-2006 at 01:14 AM.
#6
Re: What is the 62 mile bug?
Originally Posted by toast64
Yeah, I've seen that posted before, but I really don't think that's it. Last weekend I was on the highway and I watched it really closely. I was going about 60 mph, and the display updates every 10 seconds, so I was going about 1/10 mile between updates. It definitely did not change until just after 63 miles by my observation. Anyone seen something different?
#7
Re: What is the 62 mile bug?
Originally Posted by ElanC
Well, any time you reset the trip odo manually you'll see that it takes a little while for the MPG number to show up. I think that when starting from zero miles it wants to accumulate some data before showing you a number. The same may happen after the bug resets the MPG calculation, which is why there is a delay.
#8
Re: What is the 62 mile bug?
Don't know how much this has to do with it, but computers think/speak in binary - 1's and 0's. You can count from 0 to 63 using 6 bits, that is 000000 thru 111111. To get 64, you need a seventh bit (1000000). Often times when computers do goofy things related to math, it happens on the factors of 2 (1, 2, 4, 8, 16, 32, 64...). If the computer - due to a programming error - is only reading the first 6 bits of the mileage data, it would go 0 - 63 then recycle. It could be some other combination as I'm not sure how they'd handle the decimal.
#9
Re: What is the 62 mile bug?
Originally Posted by Tim
Don't know how much this has to do with it, but computers think/speak in binary - 1's and 0's. You can count from 0 to 63 using 6 bits, that is 000000 thru 111111. To get 64, you need a seventh bit (1000000). Often times when computers do goofy things related to math, it happens on the factors of 2 (1, 2, 4, 8, 16, 32, 64...). If the computer - due to a programming error - is only reading the first 6 bits of the mileage data, it would go 0 - 63 then recycle. It could be some other combination as I'm not sure how they'd handle the decimal.
#10
Re: What is the 62 mile bug?
Originally Posted by Tim
Don't know how much this has to do with it, but computers think/speak in binary - 1's and 0's. You can count from 0 to 63 using 6 bits, that is 000000 thru 111111. To get 64, you need a seventh bit (1000000). Often times when computers do goofy things related to math, it happens on the factors of 2 (1, 2, 4, 8, 16, 32, 64...). If the computer - due to a programming error - is only reading the first 6 bits of the mileage data, it would go 0 - 63 then recycle. It could be some other combination as I'm not sure how they'd handle the decimal.
But I don't think BCD's are used anymore, rather it is all done in software. So I would guess, cars with this bug has stuck at bit (or faulty overflow operation). Since only some of the cars have this, I would hazard to guess some hardware fault (bad RAM/Flash).