Archives

I am curious if the Scangage can monitor transmission temp. I see it can do coolant, and volts. I tow at times and would like those 3 readings. This would be cheaper and less time consuming than adding separate gages to my A pillar.

Perhaps we could list all the data that can be monitored for others to use in this thread.

Thanks in advance.

Depends on your car.

Using the CMNDS feature you can walk through all possible odbII commands {0000 - FFFF} and {000000 - FFFFFF}. I choose to cheat a bit. I did the following:

XXYY where XX = {01 - 0F} and YY = 00. If you get a response, record it, if the response is odd (not even) advance YY by 20 and recored the responce. Continue till you get an even response (consider no response even).

Then try XXZZYY where XX = {10 - FF} and ZZ = YY = 00. Advance YY as you did before if you get a response and it is odd (not even).

I wrote this up in one of my scangauge posts, so just look at my tips & tricks and my Prius SG post.

11011011

Forgot to tell you how to send an OBDII command.

See: http://www.scangauge.com/support/OBDIITestStatus.shtml

The link tells you how to send OBDII command {0101} on various cars. Try to reverse engineer the process to XXYY and XXZZYY.

11011011

OK... here's my better explanation
OK... Here's the first run of supported PIDs of the 2007 Prius

To find them I did the following CMNDS

XXYY where XX is the mode and YY {00, 20, 40, 60, 80, A0, C0, E0}. The return you get back is a bitmap letting you know which of next 32 PIDs are supported. If the return you get back is odd, then go ahead and advance YY by 20. I tried XX of 01-0F.

Example

0100: 4100981A8013 (odd, so keep going)
0120: 412080018001 (odd, so keep going)
0140: 4040FE1C2000 (even, so I can stop)
To decode the numeric PID to the data it gives back, look at this:
http://en.wikipedia.org/wiki/OBD-II_PIDs

11011011

So what you are saying is I would have to try different commands till I find the correct response? Somehow i would have to find my trans temp without knowing what my temp is. That will be hard.

I wonder if I brought it into the dealership and asked them to read my trans temp. Then plug the scangage in and try to get the same number as a response.

So what you are saying is I would have to try different commands till I find the correct response? Somehow i would have to find my trans temp without knowing what my temp is. That will be hard.

I wonder if I brought it into the dealership and asked them to read my trans temp. Then plug the scangage in and try to get the same number as a response.Might be a good idea. The dealership techs would have the specs that would tell them the codes if can convince them the share the gold. Problem is, the Pontiac may not report Trans temp over OBD-II.

On the other hand, some cars (don't know if 2007 cars still do) used to report both trans temp and radiator temp on a "Coolant Temp" request. So when PID 0105 got sent down, two replies came back, one for radiator temp, and one for transmission temp. I think Ron wrote some filters into SGII to only grab the radiator temp in these cases. So coolant temp can get sent back on an 0105 request. You could recognize it because it would NOT look like the radiator temp. So if fºWT reports 160 and one second later 0105 reports 120, the 120 is transmission temp (since it's impossible for fºWT to go from 160 to 120 in one second).

The other possibility is that it is being reported in a specific Vehicle OBD-II mode. The for escape does this, it's Vehicle Mode is 0x22. The Prius doesn't have a special mode for extra vehicle info, everything it reports over OBD-II seems to be the minimum required by the EPA. All the really good stuff is down at a lower level on the CANbus (something the current SG doesn't expose).

If your interested in checking for a specific Vehicle Mode for the Pontiac, or to check if 0105 reports both, you'll need the "MODE" SG is currently in. Read page 20 in your SG manual to figure this one out. Once you know the mode, we can figure out how to send the PID down the OBD-II port. I'll help with the command and decode (or you can look at this link (http://www.scangauge.com/support/OBDIITestStatus.shtml) to figure it out).

11011011

Just a slight correction, mode 0x22 is NOT an Escape mode, it is a format specified in SAE J2190. All vehicles that support this mode will use 0x22 in front of the PIDs. I have two GM vehicles so I will check them to see if I can retrieve trans temp from them, although they are MY 1999 and 2001 and use VPW protocol.

See, trans temp vs. ECT might be one of those examples of
answers from different ECUs -- although in some cases the
engine ECU might have its own "copy" of the trans temp figure
that it got from the transmission ECU, but possibly takes the
liberty of reporting it differently or as a different PID!
For someone who grew up on the internet and IETF standards
process, this sort of common mangling that happens in the
autmotive world looks like a total standards nightmare.
.
Asking an individual ECU for some of these things instead of
using the "broadcast" address [at least in the CAN IDs universe]
is probably one way of trying to limit the responses. If I
remember even vaguely correctly, transmission ECUs tend to live
at CAN ID 0x7E1, right? Where engines are 0x7e0 and anything
higher up is more or less what the manufacturer pleases?
.
_H*

Actually, transmission temp was the prime motivation for the xgauge feature being added to the scangauge. This was due to the large number of RVers who have bought the scangauge. At any rae, the new firmware is now released, so if you send your SC in, they will load the new firmware in. Ron indicated that this would be free for "recent purchasers" of the scangauge, but he obviously doesn't want to piss people off by making them pay because they missed a purchase date by a day or two. So, call first before sending it in. I know that he has compiled a list of enhanced PIDs for GM, Ford, and also the CAN Prius. Scaling and offsets are still being determined, although for Ford in general and the FEH in particular it is pretty complete.

For my Olds VPW, tansmission temp is a mode $22 PID, $1940. If you go to CMND and enter 6C10F122194001 and hit SEND, you will get back the temp in degrees C with a 40 offset (in HEX.) With the new SG firmware, you can display this in the gauge mode.