Transmission temperature Gauge

[Andy4639]

Ok,
since the Scan gauge 2 I bought want read the temperature of the transmission I have been looking at kits.
I want to add the temp gauge to my 4L80E. So where do you think the best spot for it would be? Also which kit to get. I have been thinking of this one.


http://www.oreillyauto.com/site/c/de...smission+gauge

[Hart_Rod]

Doesn't the computer monitor the tranny temp?

[solidaxel]

My Torque Pro App will read engine and Trans temp

[Andy4639]

Yes it does if hooked up. I have a stand alone harness and haven't been able to get it to pull it up. I tried all the scan gauge codes but none worked even called. They said it must not be hooked to computer, I found a diagram last night on LS1 site to check it. I hope to get it sometime.I would much rather have it read through the scan gauge than adding a gauge under the dash. Any help would be great on this.

[BR3W CITY]

Hmmm, I have the scangaugeII as well and I most DEFINATELY read my tranny temp. I can't remember, but I believe I had to add the PID to the scangauge to do this.

Try this andy; Go to your scangauge and look at the firmware. Then go to their webpage and go to the "Xgauge" section. If you navigate to the GM area, you can get lists of the PID's and the codes you need to enter to get them to work. If you locate the trans temp ID, you can add it to the XGauge function and watch it on the scangauge.

[Andy4639]

Originally Posted by BR3W CITY

Hmmm, I have the scangaugeII as well and I most DEFINATELY read my tranny temp. I can't remember, but I believe I had to add the PID to the scangauge to do this.

Try this andy; Go to your scangauge and look at the firmware. Then go to their webpage and go to the "Xgauge" section. If you navigate to the GM area, you can get lists of the PID's and the codes you need to enter to get them to work. If you locate the trans temp ID, you can add it to the XGauge function and watch it on the scangauge.

I have done this several times and it just shows a blank screen on the scan gauge. I think it's the stand alone harness may have the wire not connected. I even called Scan gauge and went through it with them on the phone. Nothing I sure wish I could get it to work though I really don't want to add the extra gauge.

For GM vehicles that use the VPW protocol

Trans Fluid Temperature (Exc Allison) 6C10F1221940(01) 046205190640 3008 00090005FFD8 TFT Degrees Fahrenheit

Allison Trans Fluid Temp (5-Speed) 6C18F1221940(01) 046205190640 3008 00090005FFD8 TFT Degrees Fahrenheit

For GM vehicles that use the CANSF protocol
Trans Fluid Temperature (Exc Allison) 07E0221940(01) 046205190640 3008 00090005FFD8 TFT Degrees Fahrenheit

Allison Trans Fluid Temp (5-Speed) 07E2221940(01) 046205190640 3008 00090005FFD8 TFT Degrees Fahrenheit

[clinebarger]

Even a swap harness will be wired for the TFT, It is part of trans control.

[Andy4639]

Originally Posted by clinebarger

Even a swap harness will be wired for the TFT, It is part of trans control.

From my understanding not all trans missions have it installed but I maybe wrong. I sure would like to have this if any one knows the codes they use pleas post them and I'll try again.
Can a scanner tool pull the temp reading up. I have a OB2 scan tool.

[Andy4639]

I've been searching all night for info guy's. Does this look right to you all.

L= temp senor yellow/black goes to red connector of ECU pin #51
M = ground grey wire for 6.0 only, blue connection pin 41 per middle and bottom drawing.

[Andy4639]

If my info in the other post is correct I have the yellow wire in spot 51 red connection. I don't have the grey in the 41spot in the blue connector. I am also thinking it's a common ground wire though.

[ls1nova71]

Originally Posted by Andy4639

If my info in the other post is correct I have the yellow wire in spot 51 red connection. I don't have the grey in the 41spot in the blue connector. I am also thinking it's a common ground wire though.

You can't expect the temp sensor to work if the ground isn't there, so that sounds like your problem. Add the wire from M on the trans plug to 41 on the PCM and it should work.

[Andy4639]

This is what I was thinking also. I just wanted to hear it from someone else. Now can somebody tell me where to get the wire connectors and how to install them?

[BR3W CITY]

http://www.wiringproducts.com/genera...ectors-sockets

[Andy4639]

Couple of local guys have told me they have some old harnesses they can pull a wire off of and give me.

[clinebarger]

Originally Posted by Andy4639

From my understanding not all trans missions have it installed but I maybe wrong. I sure would like to have this if any one knows the codes they use pleas post them and I'll try again.
Can a scanner tool pull the temp reading up. I have a OB2 scan tool.

All 4L60E & 4L80E transmissions have a TFT sensor, The 60E TFT is part of the Pressure Switch assembly, The 80E TFT is part of the internal trans harness.

Remove the trans connector & check for a ground at pin M, The harness builder may have grounded the TFT elsewhere.

If no ground is found, You can also "Case Ground" it somewhere, Doesn't necessarily have to be wired to the PCM low reference, A Low Reference is just a PCM supplied low amp "sensor" ground.

A scan tool should show a trans temp reading (Not sure on generic scan tools though)

The odd thing is...Even if the TFT is not grounded, The PCM will read it as -40 degrees because the TFT is not pulling the voltage down on the TFT sensor signal wire with resistance to ground.

The PCM sends out 5-volts on the TFT signal circuit (Pin 51)

The TFT sensor is a resistor (thermistor), which changes value based on temperature. The sensor has a negative temperature coefficient. This means that as the temperature increases, the resistance decreases, and as the temperature decreases the resistance increases. The PCM supplies a 5 volt reference signal to the sensor and measures the voltage drop in the circuit. When the transmission fluid is cold, the sensor resistance is high and the PCM detects high signal voltage. As the fluid temperature warms to a normal operating temperature, the resistance becomes less and the signal voltage decreases. The PCM uses this information to control shift quality and torque converter clutch apply.
If the PCM detects the TFT sensor resistance has no change, or an unrealistic change in a short amount of time, multiple changes within seconds, then DTC P0711 sets.

Conditions for setting DTC P0711.....

•No ISS DTC P0716 or P0717.
•No OSS DTC P0502 or P0503.
•No ECT DTCs P0117 or P0118.
•No component slipping DTC P1870.
•System voltage is 8 - 18 volts.
•The engine is running for greater than 35 seconds.
•The TFT is -40 to +70°F at start up.
•The Engine Coolant Temperature is greater than 185°F.
•ECT has changed at least 99°F since start up.
•The vehicle speed is greater than 5 mph for at least 12.5 minutes.
•The TCC slip speed is greater than 60 RPM for at least 8.3 minutes.


You can monitor voltage on the yellow/black wire at PCM & diagnose the circuit is pretty easy using this chart.

[Andy4639]

clinebarger,
Thanks for the info. I have been sick since yesterday and haven't felt like doing anything else to the truck. I will check the connector at the transmission and hope I can just ground it there some where without having to run it back to the ECU.
Yes, it being a stand alone harness they could have deleted it.

[Andy4639]

Remove the trans connector & check for a ground at pin M, The harness builder may have grounded the TFT elsewhere.

If he grounded somewhere else it should pick it up on the scan gauge I would think?

[Andy4639]

OK so now what. The "M" connection has the ground wire in it. Do I tap into it and ground it to the case are do I run a wire to the correct plug on the back of the ECU?
I don't understand why it's not picking it up if it's grounded though.
Here is the connector.

[solidaxel]

Can you check for continuity from the M side of the trans plug to the corresponding pin at the ECU, or have you already completed this?

[Andy4639]

Nope haven't done that. I just got started.
I don't know where the black wire goes to since it's not in the connection it suppose to be in. It should be in Blue 41 but it's empty.

I would have to tear the whole harness a part to do that which I don't think would be wise.

[Andy4639]

This are the locations for all the black wires at the ECU. I'll have to take the ECU out again to verify them though.Info here.

http://lt1swap.com/99-02_vortec_pcm.htm

Blue connections.

41 BLK 407 Sensor Ground (Trans) w/Case grounded o2 Sensors

53 BLK 470 Fuel Tank Pressure Sensor Ground

54 BLK 452 TP Sensor Ground

Red connections:

57 BLK 552 IAT Sensor Ground

[solidaxel]

Test all of them.............with the VOM, power OFF, one of them should give you continuity

[ls1nova71]

Not positive, but I believe you need to run the sensor ground back to the PCM and not just to ground. Try adding a wire from M to pin 41 and see if it reads. You would only have to do it temporarily to see if it works or not, and if it does, then worry about running the wire a little better.

[Andy4639]

Originally Posted by ls1nova71

Not positive, but I believe you need to run the sensor ground back to the PCM and not just to ground. Try adding a wire from M to pin 41 and see if it reads. You would only have to do it temporarily to see if it works or not, and if it does, then worry about running the wire a little better.

Tap into the black wire at M and run it to 41 on the ECU right. Leave it as is just tap into it.
I will be taking the ECU back out to try it.

[ls1nova71]

NO, don't just tap into it, that would just ground the low reference circuit to the PCM. Take the M wire out and run a dedicated single wire between there and pin 41. The pins in the trans connector and the PCM are the same, so if you have two extra ones, they will work in either connector.