Temperature/milage Computer

[mbj]

after reading thru the forums i saw that some were having problems with the temperature/mpg computer accuracy.i seem to be in the same boat with my 2005 gx470. is there a letter or notice from lexus or dealers that i could refer my dealer to so ican get this problem checked? gs400jon who had the computer changed for this problem said his dealer called the replacement the "outside temperature gage fix" so he must have been aware. thanx for reading. mbj

[The G Man]

How far off is your temp and MPG computer off by? It is normal for the MPG computer to be 2 or 3 MPG higher and the temp gauge may be off a few degree also. Usually when the temp gauge is 5 to 10 degree when you first start driving, after 10 minutes or so, it will settle down to the actual temp. The problem with determining the temp gauge accuracy is that the temp you are comparing to may be as inaccurate as the temp gauge in your GX, but in the opposite direction, therefore doubling the error. And no, there is no TSB for temp or MPG computer replacement for the GX.

[mbj]

g man after driving long enough to allow for the outside temperature to settle down it read -4 to -5 degrees.the accutate outside temperature was -8.1 degrees.yes' the mpg in the vehicle shows 2 to 3 mpg high. i dont understand how in a vehicle this expensive and sofisticated it can be considered "normal". thanx mbj

[The G Man]

I have owned 3 different cars with MPG computers and all different brand, they all read higher than actually calculation. I wonder if this is done on purpose or if it has something to do with the programming. As far as temp. is concern, its only a cheap temp sensor they put in there, a good lab. garde thermocouple will cost like $600.