# Jeep WK/WH Grand Cherokee 5.7L Hemi 545rfe transmission temperature in Celsius on Scangauge II X-Gauge

Here’s an x-gauge for **545rfe** trans. temp in Celsius, tested on my ‘06 WH hemi, and confirmed accuracy with a laser therm. on the case and oil temp probe down the dipstick tube.

It’s the same code listed on the scangauge site as tested on a dodge ram hemi, just with the MTH changed to get the value in Celsius;

TXD: **07E12118**

RXF: **046105180000**

RXD: **2810**

MTH: **00050240FFEF**

Here’s how I got to that MTH value, just in-case someone is googling like I was a few hours ago, and for me to refer to, when I’m trying to figure out another one and can’t remember wtf I did.

The DegF MTH is **000100400000**.

Which means **F=1/64*x-0** (where x is the ‘raw’ value returned from the car.).

That was confusing, because all the other temps I’ve seen are returned as either DegF or DegC and just need to convert from one to the other. I’m guessing on the 545rfe the temp is returned as DegF, but needs to be bit-shifted by dividing by 64.

So we’ve got **F=1/64*x-0**.**C=5/9*(F-32)** (thanks to Fud for that one.).

Or;**C=5/9*(( 1/64*x-0)-32)**

Which simplifies to;

**C=5/576*x-160/9**

The scangauge can only subtract whole numbers, so I round

**160/9**down to

**17**(which means the gauge will read about

**~0.7deg high**… better than low IMO.);

So the MTH needs to be;

**C=5/576*x-17**

Which in HEX (using 2’s compliment notation for -17) is

**00050240FFEF**.

This was originally just a post on the AJOR forums, I’ve replicated it here just incase another server crash looses some data.