I was playing with my scangauge and notice that as the trans warms up the voltage drops is that suppose to happen if so does anyone have a chart showing what the voltage should be at certain temps

 

Why would you care? If you have a Scan Gauge then just read out the transmission temp directly.

But, if you really want to know I believe the sensor is the same as the engine oil temp sensor. Here is what I have for it ...

K Ohms__Volts____TempF___Temp C
826______4.75______-32______-36
785______4.75______-30______-34
575______4.73______-22______-30
525______4.72______-20______-29
365______4.68______-10______-23
300______4.65______-4_______-20
250______4.63______0________-18
192______4.6_______10_______-12
173______4.55______14_______-10
139______4.49______20_______-7
103______4.4_______30_______-1
98_______4.38______32_______0
64_______4.18______40_______4
59_______4.13______50_______10
43_______3.92______60_______16
37.3_____3.8_______68_______20
33.6_____3.73______70_______21
26.8_____3.53______80_______27
24.3_____3.44______86_______30
21.5_____3.32______90_______32
17.2_____3.08______100______38
16.1_____3.01______104______40
13.9_____2.84______110______43
11.2_____2.59______120______49
10.9_____2.56______122______50
9.34_____2.38______130______54
7.55_____2.11______140______60
6.28_____1.89______150______66
5.34_____1.72______158______70
5.32_____1.71______160______71
4.48_____1.52______170______77
3.84_____1.37______176______80
3.75_____1.35______180______82
3.17_____1.18______190______88
2.8______1.09______194______90
2.68_____1.04______200______93
2.2______0.88______210______99
2.08_____0.86______212______100
1.87_____0.78______220______104
1.56_____0.67______230______110
1.33_____0.59______240______116
1.19_____0.53______248______120
0.38_____0.17______CEL Below This

 

with trans temp at 80* I have 2.66v

 

Scangauge is showing trans temp to be 101 and 2.27v

 

Good question then, maybe they are different.
I'll do a little research on the subject.

 

I will be able to use a alldata system on Monday do you know if it would be on alldata.

I know my temp sensor is correct cause when the truck has sit all night the temp will be a couple degrees different then outside temps i'm just trying to find out ifthe voltage is correct with the temps