04 4X4 TRANS TEMP

[TEXCOASTIE]

I HAVE AN O4 REGULAR CAB SHORT BED 4X4 HALF TON. I GOT AN AUTOMETER TRANS TEMP GAUGE FOR CHRISTMAS I WAS WONDERING IF THERE WAS A SENDING UNIT ON THE TRANS THAT I COULD TAP INTO AND RUN OT MY GAUGE SINCE EVERYONE IS GETTING A NEW CLUSTER AND REPROGRAMMINGTHE MILES AND THEIR TRANS TEMP IS WORKING THERE HAS TO BE A SENDING UNIT ON IT SOMEWHERE THANKS FOR ANY INFO

[GM-Tech]

There's a thermistor inside the trans fluid pressure switch that provides a signal to the PCM. The PCM in turn provides a temperature message to the cluster over the class 2 data line.

 

I think somewhere there might be a chart that give the thermistor's resistance at various temp readings. The odds your gauge's input needs would match this exactly is doubtful, unless it was designed for that specific application.

[GM-Tech]

I knew there was a chart for temp vs. resistance, but it's in a table format, so it'll take some work to understand this...

 

Transmission Fluid Temperature (TFT) Sensor Specifications

 

Temperature

Temperature

Minimum Resistance

Nominal Resistance

Maximum Resistance

Signal

 

°F

°C

ohms

ohms

ohms

Volts

 

-40

-40

90636

100707

110778

5.00

 

-22

-30

47416

52684

57952

4.78

 

-4

-20

25809

28677

31545

4.34

 

14

-10

14558

16176

17794

3.89

 

32

0

8481

9423

10365

3.45

 

50

10

5104

5671

6238

3.01

 

68

20

3164

3515

3867

2.56

 

86

30

2013

2237

2461

1.80

 

104

40

1313

1459

1605

1.10

 

122

50

876

973

1070

3.25

 

140

60

600

667

734

2.88

 

158

70

420

467

514

2.56

 

176

80

299

332

365

2.24

 

194

90

217

241

265

1.70

 

212

100

159

177

195

1.42

 

230

110

119

132

145

1.15

 

248

120

89.9

99.9

109.9

0.87

 

266

130

69.1

76.8

84.5

0.60

 

284

140

53.8

59.8

65.8

0.32

 

302

150

42.5

47.2

51.9

0.00