Transmission temperature monitoring with OBD2

[johncg]

I've seen posted that one can monitor transmission temperature using OBD2 code 21D9. While this code does return a value I'm not sure this is correct. I've even tried using the plug in for Torque app to make adjustments via the equation function. Anyone have advice or alternative PID codes to try for a 2007 4Runner with V6?

 

[jdkilroy]

I think it depends on the software you are using to access the OBD system.

There are a series of well published codes for the Scan Gauge and others but those are specific to their operating software.

If you are talking about the raw output codes then I cannot help.

 

[johncg]

So, I am using the latest version of Torque and a plug-in called Torque Scan. This plug-in enables you to monitor any PID code and to adjust any values being reported as needed.

When monitoring the 21D9 code, the system returns a value around 14 or so while in park (engine one) which may be ok but the issue I see is that this value chages to zero once the tranny is put into drive.

I wish I had access to a list of PIC codes for the 2007 4Runner V6... or at least a confirmation that 21D9 is the PID code for the transmission temperature. There may be 2 temp sensors on this model so there would likely be a second PIC code as well.

 

[jdkilroy]

I believe there are two sensors/outputs for tranny temp. One monitors sump pressure the other one (I believe) is in the vicinity of the torque converter and has a much more volatile temperature value/output. That said, I think you may be keyed into a accessory code output since clearly the output value should escalate once the transmission is engaged.

Sorry, but a programmer I'm not.

Edit: That may be a solenoid position output code you are reading. That change would make sense when you put it into gear. The solenoid output values would reflect only two states; "on" or "off"

 

[MikeInNH]

I don't think you can directly monitor the temp. It may send a signal to the ECU IF there's a problem..but I don't think there's no temp sensor that's sending out the temp constantly.

 

[johncg]

what makes you think that the transmission temperature cannot be monitored unless there is a problem?

 

[ebg18t]

I believe we have an idiot light that triggers if the tranny temp gets too high. Now I don't know of that sensor can display/transfer the data to a obd2 reader. I thought I recalled someone using a scan guage or ultraGauge to monitor tranny temps, it was 6-8 months ago if you want to search.

 

[jdkilroy]

I have programmed my Scan Gauge to display constant tranny temp. I keep a close eye on it while wheeling to see how my driving and mode selection affects tranny temp.

Also reassuring to monitor when I'm pulling near or at tow limit with fully loaded horse trailer.

The following page from the service and repair manual indicates that there are two separate temp sensors/outputs on my transmission (V8: A750E).



Edited earlier post re output value of 21D9

 

[MikeInNH]

what makes you think that the transmission temperature cannot be monitored unless there is a problem?

Because the there would have to be a temp sensor that you can PHYSICALLY tap into to get the reading of what the temp is. The real question is..."What makes you think there is one?" And if there is one..then WHY doesn't Toyota have a temp gauge??

 

[sonerick]

Because the there would have to be a temp sensor that you can PHYSICALLY tap into to get the reading of what the temp is. The real question is..."What makes you think there is one?" And if there is one..then WHY doesn't Toyota have a temp gauge??

I also use my ScanGauge to monitor trans. temp.

MikeInNh, what makes you think there are no temp sensors? Not only does the FSM reference two sensors, but many people here are able to monitor their trans temp using a ScanGauge or UltraGauge. People have also confirmed their accuracy with an IR temp gun.

Toyota probably doesn't have a trans temp gauge for the same reason it doesn't have a battery gauge, or an oil pressure gauge (both of which my old Cherokee had). The general populous just doesn't know enough or care enough to make it worth the extra cost, especially when Toyota can program in an idiot light instead to warn owners when there is a problem.

 

[johncg]

I am still hoping that someone on this forum with a 2007 4Runner V6 will post and say that they can monitor transmission temperature. I have not been successful yet using an OBDLink (multiprotocol OBD scan tool) and the Torque app on my android.

 

[JB.]

johncg,

Lots of information in the thread below.

http://www.toyota-4runner.org/4th-gen-t4rs/83700-can-odb-dlc-used-monitor-real-time-temps.html

 

[08T4R]

I also have a scan gauge and I can tell you it reads my temp real time. Had to put in the x gauge code. If there wasn't a temp sensor how would it be possible to enter check mode and get a light on the dash at certain temps? It doesn't just magically know the temp. As far as using Bluetooth obd plug and torque, couldn't tell ya how to program that as I've never done it.

 

[johncg]

I see in previous posts that there has been a case where two temp sensors were able to be accessed via the OBD interface. At this point, I'd settle for either one since I have not been successful (yet). I have a 2007 4Runner V6 and an OBDLink (multiprotocol OBD scan tool) and the Torque app on my android.
In the meantime, I have attached a type K thermocouple to the tranmission hose leading to the radiator where it mounts to the radiator.

 

[johncg]

Here is what I need to learn from this forum:
the owner of a 2007 4Runner V6 is successfull in monitoring transmission temperature using Torque app for android (or apple) with one of the available OBD bluetooth devices.

 

[sonerick]

It looks like a few people were successful in the link provided by J.B. Maybe you should PM one of them.

 

[johncg]

I review the thread from JB and learned the following:
- Allegro has a 2007 T4R. He report "No tranny temp, no oil temp"
- SteveC5000 reports "ScanGauge II with the X Gauge feature seems to be the only way"... but he is not specific about which truck this worked on.

I posted to the thread to see if anyone there has been successful with my configuration. still looking....

 

[sonerick]

Page 2, post 23. From LEO98 (07 V6):

"Just got the Torque app and BT ELM off Amazon. Seems to be working great so far...wish I had a few more PIDs that worked.

I noticed that my Transmission Temp and Coolant Temp readings are just about the same. Where or at what points (gauges/PIDs) are these readings?

I've also noticed that my Torque app gives me "Trans Temp 3" (not 1 or 2)....
What am I missing?

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[sonerick]

Page 2, post 26. Also from LEO98:

"playing around with Torque info
Just posting a graph I made from the Torque information. I initially posted both Trans Temp and Coolant Temp, but my numbers are basically mirror images.

Nice program...probably use it on long trips and to compare how the T4R operates when I haul my boat.
Attached Images
File Type: pdf Enginetracking.pdf (102.0 KB, 18 views)
File Type: pdf CoolvsIntake.pdf (93.6 KB, 19 views)

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__________________
07 SR5 V6 4WD | FJ Front | OME 895E | Bilstein 5100s (.85) All-Around | WeatherTech Floor Mats | DEEZA Front Endlinks | GoodYear Silent Armor | Rear Diff Breather |"

 

[sonerick]

Looks like LEO98 has an '07 V6 and has played around with it. Maybe PM him.