engine clock

[Reefermax]

anyone experience the engine clock resetting itself back to zero? Really perplexed as to why it would do that.:confused:

[blksmok]

I believe if the ECM is without power for a period of time (not sure how long) it will reset the engine hours to zero.

[Kevin G]

Mine was zero one morning when I started it and counted back up for a couple days then I noticed one day it was back to reading where it was supposed to be. Never did figure out why though.:confuzeld:

[subman]

I believe if the ECM is without power for a period of time (not sure how long) it will reset the engine hours to zero.

Not sure I buy that, you can change ECM's and the clock still works. My engine hour meter in my 1/2 ton gmc gasser resets itself once in a while have no idea why.

[blksmok]

Not sure I buy that, you can change ECM's and the clock still works. My engine hour meter in my 1/2 ton gmc gasser resets itself once in a while have no idea why.

I have two ECM's (the original, and one I use to run my EFILive tunes). Last time it was at the stealership with the original ECM in it and my 2nd ECM was out for a couple weeks, my Engine hours were reset to 0 when I put my 2nd ECM back in.

I only noticed because I read someone saying the dealership can tell if you've switched your ECM because it zeros out and the engine hours won't jive with the miles on the odometer.

I paid attention when I put the 2nd ECM back in and sure enough, 0 engine hours.

Just to double check my numbers, I just went out and looked at my engine hours.

I currently have 301 engine hours listed. This is with my 2nd ECM plugged in, which I run 95% of the time, and have since just a few thousand miles on the truck. That being said, it has been swapped out with the original ECM a few times. Apparently, 301 engine hours ago was the last time.

Regardless, the truck has 55,000 miles on it. If the engine hours are correct and have never been reset, that would mean my average speed for the last 55,000 miles has been ~183 MPH. :eek:

I drive fast, but not THAT fast! ):h

[h2oskibumz]

Mine did that several times in a 3 or 4 month period. Then it quit doing it.

Interestingly enough, when I had the motor out (and ECM unplugged for about 3 weeks) it didn't zero out then...

I attributied it to rogue crazy demon electrons...

Never thought that it could be some sort of tattle tale sign that the ECM had been changed. That is an especially interesting theory since I always thought the only place hours and ODO records were actually stored was in the cluster. New cluster, or one out of a wreck and you get the miles/hours of the wreck and have to have it programmed back right.

[ripmf666]

I have swaped ecms and had the power off for a few months and never had this happen. I just had it happen now lol

[CBRJohn2000]

Mine reset itself a few weeks ago, and I have never had a power failure to the ECM since I bought the truck. I use the Edge so I don't reprogram the module......it's weird, and my curiosity would love an answer, but I could llive without it if it never gets figured out! ;)

[tinman22]

mine just reset itself last week I thin kit has a grand total of 22 hours on it currently. at almost 100K miles

[Reefermax]

yikes, i wonder if it has anything to do with that small fire last week from the blower motor harness? ):h

[subman]

I've switched ecms many times in my old 02 dmax and never had that happen. my 06 gasser seems to like to do it every 100 hours or so.

[Reefermax]

too bad the old age clock on me doesnt reset...):h