Transmission temperature Gauge

[Andy4639]

Well that maybe harder than I thought. I don't have the wires to do that. What do I do with the wire coming out of the trans connector now if I take it out of the connection?
M- is a ground so what difference would it make if I just tap off of it?

[ls1nova71]

M isn't a standard ground, it's the low reference to the PCM for the trans fluid temp sensor, which is a ground in a sense, but not a ground to chassis ground, if that makes sense. When you take the black wire out, just leave it for the time being, and hook the wire from M to pin 41. If you want to PM me your address I will send you a couple of wires with pins on them and you can try it. Otherwise, you will need to find out exactly where that black wire that is in M now actually goes. It's possible it goes to the PCM, but is just on the wrong pin. A continuity test would find out for sure.

[Andy4639]

53 BLK 470 Fuel Tank Pressure Sensor Ground , this is on blue connector of ECU.
This connection on the ECU has continuity to the M connection on the transmission connection.

[solidaxel]

Sounds like you found your transposition!

[Andy4639]

Originally Posted by solidaxel

Sounds like you found your transposition!

So what do I need to do to get it right?

Change it to 41 are tap off 53 over to 41... what?

[solidaxel]

If you are positive #53 = goes to the Black "M" on the trans plug remove 53 black from the ECU connector and place it in the #41, test with VOM from pin side of trans plug "M" to #41 Is #53 location on the ECU even in use, pressure in tank, do you even need that?

[Andy4639]

Originally Posted by solidaxel

If you are positive #53 = goes to the Black "M" on the trans plug remove 53 black from the ECU connector and place it in the #41, test with VOM from pin side of trans plug "M" to #41 Is #53 location on the ECU even in use, pressure in tank, do you even need that?

I have no senor in the tank that I know of that I installed. The tank is out of a 93 Suburban. There is no senor in it as far as I know.

I ran continuity checks on both wires. 51 which is yellow TFT senor wire. Checked good.

I checked "M" as well to blue connection at 53. It was good.

Next question how do I get the connector apart from ECU 53?

[Andy4639]

ls1nova71,solidaxel

Thank you both. I got it working. I hooked it back up and nothing. Had to reprogram the Scan Gauge. I had programed it last for the Allison transmission just to see if it would work. Per tech support at S/G, all is good! I have a reading. I'll take it for a drive later and see how it does. I have to put the glove box back in now.
I'm so happy!

[solidaxel]

............... You did all the work !!

[Andy4639]

Originally Posted by solidaxel

............... You did all the work !!

Yea but you both directed it!

[Hart_Rod]

Originally Posted by Andy4639

Yea but you both directed it!

What about me, it was my suggestion...............JK...glad you got it working.

[Andy4639]

Originally Posted by Hart_Rod

What about me, it was my suggestion...............JK...glad you got it working.

To everyone who posted on this for me, thank you! Thank you!
That why I love this board it the people are willing o help each other.

[Andy4639]

Just drove the truck for about 7 miles real quick since it's fixing to start raining and sleeting snowing freezing rain whatever it's going to do. The temp started at about 65* I waited for it to climb before I took the first picture. It's 50* out side but dropping. The TFT is working! Thanks guy's!

[clinebarger]

I'm glad you got it working!!!!

But this IS very odd, It should have worked in pin 53, Not only because it is also a Low Reference, All 99-02 F-bodies use pin 53 as the TFT ground & Pin 41 is not used.
This is the reason why your harness is pinned like that.

I know none of this matters now, But as a mechanic I like to know why it didn't work.

[Andy4639]

The only thing I would say is maybe the pin wasn't set in 53 good maybe. It looked fine to me though.
I wonder if it has to do with it being a ground are low reference ground. The 53 is a normal ground. 41 is a L/R ground...Right

Truck 1999 5.3L Connector C1 BLUE
53 BLK 470 Fuel Tank Pressure Sensor Ground

[Andy4639]

I got to drive the truck one time and that was only a short 7 miles. Been snowing and raining ever since. Plus was sick most of the time. Now I'm back to working 12hr nights. Oh well maybe next week I can drive it.

[MattPSU]

Originally Posted by solidaxel

My Torque Pro App will read engine and Trans temp

I'm having the same issue as Andy, but I'm using Torque Pro, and it's not showing any transmission temperature. Did you have to do anything in the App to get it to show this data? I've added both versions of the trans temperature gauge, but neither gets a reading.

I checked continuity and everything checked out ok. I'm using a re-worked stock harness, so everything is in the correct location.

Any ideas?

[LostMy65]

I did a google search about using a water temperature gauge for the transmission fluid temperature gauge, and many say it'll work.

[Andy4639]

Originally Posted by LostMy65

I did a google search about using a water temperature gauge for the transmission fluid temperature gauge, and many say it'll work.

I fixed this problem with my wiring harness. I bought a scan gauge 2 scan tool which hooks straight into the ECU and you can use it as gauges. Mine wasn't picking up the trans temp, and after several month's over a years worth I got to the problem which was a ground issue in my wiring harness. All is good now. Yes a water and trans gauge work on the same idea so they should work for either system.

[low82c10]

I am going to attempt to revive this post, I am having the same problem. Except I am using a blue tooth obdii adapter and the app called torque.

I verified that the pins on the transmission plug go to the correct plug at the computer with continuity. When i open the torque app everything is good except the trans fluid temp?

[MattPSU]

Originally Posted by low82c10

I am going to attempt to revive this post, I am having the same problem. Except I am using a blue tooth obdii adapter and the app called torque.

I verified that the pins on the transmission plug go to the correct plug at the computer with continuity. When i open the torque app everything is good except the trans fluid temp?

There's an extra PID setting you need to add.

In Torque, Go to Settings > Manage extra PID's/Sensors > GM and then find the transmission Fluid Temp options. There are two. I can't remember which one I used, but you may have to try them both.

Good luck!

[BR3W CITY]

If you do a little creative google-fu, you can find the complete list of GM PID's. Its not a single published document, but between the available stuff from AllData, AeroForce, and GM's own tech, they are all out there for your consumption.

*fwiw, there are also a ton of PID's you'll never use, which can be used for fun things if your willing to experiment.

[BR3W CITY]

Ok I dug around in my PDF collection and found some stuff I downloaded a while ago.
Most companies (whether "GM" or not) used something called SAE J1850, which is just a title for an industry-accepted standard for hex-based language protocol for controlling ECM, TCM and BCM functions. Basically, when everyone "agreed" on OBDII being the standard, they also "agreed" on a basic language to be used for programming and error coding. (DTC codes for Errors, PID's for sensor function channels).

Its a hex based language, so numbers 10 numbers (0-9, with 0 being considered a number), and A-F, being used in combinations. Those combinations (called strings) are usually affixed or prefixed with a 1 or a 0 to denote On/Off or Open/Closed. Manufacturers can use strings that aren't reserved called Enhanced or Extended PID to control brand-specific or special equipment goodies.

This is what most manufacturers used, or used as a base up until CANBUS/GMLAN/CANII overtook it by the late 2000's.

Here's the list of GM specific PID's for the pre-canbus era. They have the others as well if you navigate the page.


http://www.scangauge.com/support/x-gauge/gm-specific/

[Andy4639]

Driving mine I have noticed the Trans temp will read higher than the water temp. Not hot but a few *'s higher sometimes even though they are both below 185*.
My water temp most of the time is 179* with no fans. Some times the trans temp will read 182-183.
Just something I have noticed.
I have both coolers hooked up.
Anybody else noticed this?

[foamypirate]

Originally Posted by Andy4639

Driving mine I have noticed the Trans temp will read higher than the water temp. Not hot but a few *'s higher sometimes even though they are both below 185*.
My water temp most of the time is 179* with no fans. Some times the trans temp will read 182-183.
Just something I have noticed.
I have both coolers hooked up.
Anybody else noticed this?

Hmm, that's interesting. I've never seen my trans temp go over 160*, but then again, I am running a huge cooler after the radiator cooler (Long Tru-Cool LPD4590 cooler). Is your external cooler plumbed before or after the radiator?