Hi, I have an '06 3500 Megacab. Just turned 40k. I noticed the other day that the overhead temp. gauge was showing off the wall wrong temps. After cycling the ignition it will sometimes correct itself but will go off the wall again. Just wondering if there is something to look at that may cause the erroneous readings and if is going to be a warning of " troubles" to come.

Thanks in advance for any advice.

Big Mega in NJ

 

I have noticed mine will sometimes show a -47 temp or just 20-30 degrees below the actual but after a few minutes of driving it corrects itself. I don't think there is any problems with it, just a funky reading by the sensor at times.

 

Mine would read what ever it was when I shut it off and would read correct after driving couple miles or so....reciently went in for a service an they did all the updates now its correct at start up.

 

Thanks for the input. Mine seems to be all over the board.
From -47 F to +21F. Sometimes it will correct itself on the next startup sometimes not. Hasn't been to the dealer for any services so there has been no opportunity for updates from them. I'll just have to keep an eye on it.

Thanks all.

 

I would check the connection. It is on the drivers side in front of the radiator. I have seen it but not near my truck this weekend to better describe location. My readings have also gone crazy of a few days, usually when pressure washing the truck with the winter front on. I think the winter front holds the moisture and freezes, messing up the readings for a while. Just an idea.

 

Mine has done it a few times. I usually just turn off the truck and restart it and it fixes its self

 

Mine has done it since day one, especially when I go down to really hot desert temps. At startup it will read -47* on a 105* day. Couple of miles and it's back to the right temp. I had it on my list of stuff in Dec 2007, and they re-flashed my ECM with all the latest software/firmware. When summer cam around last year, hotter than all get out, 110*s, my overhead once again told me it was -47*.

I make sure that the sensor out by the radiator is clean, but in high heat or intense cold, it always starts out at -47*s.

The flash or download they did has my overhead reading right on when it comes to fuel mileage, it agrees with hand calcs, and it has not reverted to it's old lie-meter habits.


CD

 

Do you have any more info on that pcm flash update? I would love to get my overhead reading correctly!