Over Drive

[Bill]

Originally Posted by PopBeavers

I get paid to write programs of large computer systems. I took a JAVA class in 1999 and have never had a reason to use that language. I wonder what I could do with a bit of hardware and my own software. There might even be some free down loadable source code for me to start with.

Wayne -

Let us know if you do this. My concern, born out of ignorance, would how to find out the format of the data that circulates over the OBDII bus. I don't know anything about the format, and I don't know if it is standard from one manufacturer to another.

I think that the signalling format has finally standardized. There used to be several busses - CAN bus, ISO bus, PWM bus, etc. I'm not sure what the standard is, but at least hardware interfacing will be simpler now.

Let us know!

Bill

[Edit - In looking up bus names, I ran across this site that ought to help. http://obddiagnostics.com/obdinfo/msg_struct.html ]

Originally Posted by mtnguy

Wayne, I am so glad that I can help you stimulate the economy.

Give everyone a report after you get the ScanGauge II and after you have used it for a trip or 2.

I can't buy any more toys (er, I mean tools) for my towing needs......with the ScanGauge, Pressure Pro TPMS, and a Tom Tom on top of my dash, I just don't have any more room.

We added two ATVs and a motorcycle last year, along with an ATV trailer. This year we added another motorcycle.

So when we go camping I drive the 2500HD towing the TM and my wife drives the 1500HD towing the ATV trailer.

There are no toyhaulers that will fit in my garage where the TM is stored.

In the year we have had the 2500HD we put 3500 miles on it. The on-board computer said the oil was half used, but I changed it at the one year mark anyway.

I may not stimulate the economy buying gas ($1,000 per year per truck), but I did what I could to help GM.

Originally Posted by ED-n-KEL

My son ran his car off the interstate and into the woods, because he had is laptop on the seat next to him fiddling with it.
The car was totaled. He escaped with a severely bruised hip and lots of other cuts and minor bruises...(thank God for seatbelts!).
Another first hand experience I would not recommend.

My son, in his college days, was changing a CD in the radio, in the dark, on a two lane highway, which resulted in a bit of weaving, while speeding a bit.

The officer that pulled him over was surprised to find out that he was not drunk. He was certain, with all the weaving that my son was doing, that he had a drunk driver to pull over.

Originally Posted by Bill

Wayne -

Let us know if you do this. My concern, born out of ignorance, would how to find out the format of the data that circulates over the OBDII bus. I don't know anything about the format, and I don't know if it is standard from one manufacturer to another.

I think that the signalling format has finally standardized. There used to be several busses - CAN bus, ISO bus, PWM bus, etc. I'm not sure what the standard is, but at least hardware interfacing will be simpler now.

Let us know!

Bill

[Edit - In looking up bus names, I ran across this site that ought to help. http://obddiagnostics.com/obdinfo/msg_struct.html ]

My comment was a bit tongue-in-cheek. I doubt that I will ever actually do this. I would if I was retired, but I just don't have the time with all the other interesting things I want to do.

The link to the documentation would certainly be helpful. Apparently the way these things work is the car sends text messages in a particular format. Each message contains specific information.

Think of it like running AOL IM or any other instant messaging program. It would be like getting a bunch of messages back to back continuously and you can ignore the boring ones and capture the ones of interest.

I suspect it is not a continuous data stream. I suspect that it is essentially client server, much like a web browser. You send down a text message as a command of what you want and the computer in the car sends back the answer to your question.

The cable that my nephew has is just an OBD-II plug on one end and a standard RS232 (serial port) plug on the other end. He plugs it into the serial port on his laptop just like you would plug in a modem.

With proper software it is quite easy to capture all data traffic in both directions across the cable. You would probably need to know how to read hex (hexadecimal) data because it may not be printable text (ASCII).

Once you have the data you could dump it into a couple of files using commas to separate the values (CSV format) which could then be imported into a spread sheet (MS Excel).

Anyone that has take a couple of JAVA programming classes should be able to figure it out. But, it will likely take a fair amount of time. I don't think it is difficult, just tedious.

Capturing the data and dumping it in a format suitable for Excel would be pretty easy. Generating real time displays while driving down the road would be a bit more difficult, at least for me. There are probably some free software packages in JAVA that would do most of it, but it would take me a lot of time just doing the research to find the JAVA packages.

I think this would be an excellent senior project for a high school computer geek.

If you happen to have such a child, I would be happy to consult.

Toyota 4 Runner V8 (2008).
Here is, to me, alarming information on page 167 of my factory owners manual.
"Do not continue hill climbing or hard towing for a long time (how long is "long"?) in "3", "2", or "L" position. This may cause severe automatic transmissin damage from overheating. To prevent such damage, "4" position should be used in hill climbing or hard towing".
Now my interpretation of this statement is to use overdrive for towing unless climbing a short hill!
This is contrary to what I have been told in the past and sure contradicts good information throughout this thread.
I contacted my local Toyota service department and they said to downshift on hilly terrain.
I contacted Toyota customer support, they said to downshift when on hilly terrain.
Of course I agree with the downshift policy.
I suggested the customer service folks might want to take a look at the owners manual and consider a change in their statement or they are goiing to pay for a lot of burned up automatic transmissions.
They said they would make a note of it, yeah sure!

[ThePair]

Originally Posted by ib4classics

Toyota 4 Runner V8 (2008).
Here is, to me, alarming information on page 167 of my factory owners manual.
"Do not continue hill climbing or hard towing for a long time (how long is "long"?) in "3", "2", or "L" position. This may cause severe automatic transmissin damage from overheating. To prevent such damage, "4" position should be used in hill climbing or hard towing".
Now my interpretation of this statement is to use overdrive for towing unless climbing a short hill!
This is contrary to what I have been told in the past and sure contradicts good information throughout this thread.
I contacted my local Toyota service department and they said to downshift on hilly terrain.
I contacted Toyota customer support, they said to downshift when on hilly terrain.
Of course I agree with the downshift policy.
I suggested the customer service folks might want to take a look at the owners manual and consider a change in their statement or they are goiing to pay for a lot of burned up automatic transmissions.
They said they would make a note of it, yeah sure!

I'm fairly sure that this recommendation is because the automatic Toyota transmission will NOT lock the torque converter in 3, 2, or L, only in 4 (and D). From what I understand, an unlocked converter means higher transmission fluid temps, and therefore damage potential over time. It will lock the converter as long as the gear selector is set to 4 or D, even if the engine downshifts to 3rd.

If you have a D setting as well as 4, I think the "downshift" recommendations were to shift down to 4, and just leave it there. On the Toyota sites there is debate as to what's the best gear to use for towing, 4 or D. No one advocates 3 or less unless it's absolutely required for hillclimbing ascents, or engine braking on a steep or long grade. The overall consensus I've read is to use D if you're on flats, and 4 if there are any hills making the transmission search or shift. Both these options will allow for torque converter lockup, which is good for trans temps and overall transmission longevity.

This is my best understanding of Toyotas and towing, but I don't consider myself any kind of expert.

That's more of an explanation than the Toyota service folks gave.
I only have 4D then 3rd etc..
Thanks for passing along the information.