fuel temp sensor

[King]

My service engine light came on for what I thought was no reason, come to find out you can not plug in the block heater on a duramax unless it is below zero degrees. Any info on this would help since I live in alaska and even at 15 degrees it seems to start hard...

02 crew
black 4x4 short bed
duramax/allison

[Willcoc]

I plug the block heater in on mine with no problems even at 30F. Been doing this for the last few years with no problem. Did need to replace the factory cord in this winter. Most of the time I use a timer to reduce the power usage but have plugged in a warm truck and left it pluged in all night long. Plugged it in warm earlier this week and the next morning the temp guage read 170 when I turned on the key (was 10F that morning). But dropped pretty fast when it started. Never had a code set from this.

[jackrabbit]

Some trucks have this problem and some of them don't. Supposedly there was a reflash for the computer that would fix this, but I don't know for sure which one it is.

Your statement though that your truck starts hard at 15 would be more of a consern. I have had mine start up with no problems and not plugged in as low as -20F. I have also plugged it in all nite at +30F just to see if it would thow a code and it didn't. I know that doesn't help you out, but I would think that the dealer would be able to fix this for you.