I agree that there is not much point in a gauge that doesn't give the driver an accurate idea of what is going on.

I'll have to try putting the IC in engineering mode on my truck but your response indicates that you are experiencing the same thing as I am with mine. I wonder if there is a way to calibrate the sensor?

 

The gauges are digital or computer controlled. The sensor output feeds the TCM (transmission Control Module) and puts the reading onto the system communication bus. The IC (instrument cluster) reads the value and controls the gauge. It is likely the IC programs the gauge to read near 50% when the trans temp is within a nominal range.

I'll check the coolant temp gauge and see how that performs. But it looks like I'll be adding a real gauge somewhere down the line.

 

Anyone know if any aftermarket programmers offer a calibration for the guages? That way you don't have to add another guage, just make the existing one work more accurately.

 

No but you can get a tuner/programmer (Edge, Gryphon, SCT) that will display real time values (much more than what the IC displays). In addition, you can get custom tunes for your mods (tire size, CAI, exhaust).

 

I put the IC in engineering mode when I left work tonight. Ambient temperature was 22 F. When I started the engine, the transmission temperature indicted by the IC in engineering mode was 0 degress C. After driving about 1/4 mile, the trans temperature was up to 12 deg C. At this point, the gauge needle was on the cold side hashmark. Within 3 miles, the trans temperature had increased to 31 deg C. At this point, the gauge needle was indicating mid span. It stayed there for the next 4 miles until I stopped for about 10 minutes at a grocery store.
When I restarted the truck the trans temperature gauge only rose to about 1/4 span yet the trans temperature was the same temperature as when I shut the engine off (32 deg C).
I drove another 5 miles to my house at which point the trans temperature was 52 deg C and the gauge was indicating just shy of mid point. Out of curiosity, I shut off the engine for 15 seconds and then restarted it. The trans temperature was still 52 deg C but the gauge only went to just off the left (cold) side hashmark which is less than 1/4 span.