DanStew

I am curious to know if there are any freeware or shareware programs available to connect my laptop to the truck to check it out? I know i will need to purchase a cable from the truck to USB or serial. I ahve seen them but seems to be for GMs, I am curious to see if anyone here has done this instead of just reading the blinking lights off the dash.

MMA_Alex

yup. its called a paperclip.

do a search.

DanStew

Geeeee, That was a rather nice post.

Unfortuantely i did a search. I am looknig for shareware programs for this task. I would like a differnt approach than a paperclip.

space-junk

iTrader: (1)

No... but heres a link to a guy thats making one...
https://www.yotatech.com/forums/f116...81/index2.html

MMA_Alex

i swear your post was asking about an odb code scanner...if you want a code scanner its called a paperclip.

DanStew

That was the post that gave me the idea to have a look. Definately amazing on what the guy is doing.

Here is a site with a cable, but looks to be for the vette crowd
http://www.obd1.com/

space-junk

iTrader: (1)

IIRC there is no "diagnostic port" on our yotas... maybe some of the newer ones, but ours dont... the only way to do it would be to fab up a scanner like that guy in the thread i posted is doing...

claudebadly

on my 2000 yota theres a obd2 connector. but on the older yotas like space junk said there is not a diagnostic connector.
havent looked into it, but it would be awsome if there was a cheaper software program than "eaze" that we could hook up our laptops to our trucks and see whats going on.

DanStew

Sucks to think there isnt a port, but cant make something when there aint anything. But i wonder though, the other member making that scanner tool. If the code he is using can be made to work on a PC. Because he is making the scanner with its own dialog box. A laptop would just make it easier, jsut use the code isntead of making the entire thing. But then again i stopped trying to program a long time ago.

space-junk

iTrader: (1)

in his posts he says that you could just hook it up to a laptop and download all the info into a laptop...

just gotta read a lil bit...

abecedarian

there IS a diagnostic port...
... but that requires hardware to interface to the port which would then provide an interface to the software.

so you can't just ask for a shareware program to check the codes... you can't even get codes from an OBDII system without HARDWARE to interface to the system.

Noltz

The short answer is no, there isn't. There are packages available from various manufacturers (I use Snap-On) that, with the hardware provided, allow you to hook a scanner (or in your case, a laptop) to the vehicle and retrieve the trouble codes & read data streams. Pre-OBD2, the communications are VERY slow, so trying to graph your 02 output to see if you're running rich or lean is useless. It's equally useless in say, a TPS voltage sweep, as the refresh rate is agonizingly slow.

In all, do a search for "How to retrieve codes" or "Trouble Codes". It will show you how to make a small jumper between the proper connectors on your Data connector, and count the number of times the Check Engine light flashes in sequence. Taking those two-digit numbers you can come back and look up what the codes mean, then fix the problem.

If you do not have a Check Engine light on currently, and just want to look at the data the ECU is seeing, it's easier to find another hobby. Or look into MegaSquirt - the completely programmable ECU. You can fuel inject anything from a V10 Viper to a 5hp Tecumseh.

ahickman

DanStew,

The board I made simply samples either the logic state or the instantaneous voltages being sent to the ECU. Currently it uses 10-bit analog to digital (ADC) converters to sample and then display the sensor values. The speed of the microcontroller is around 8 MHz and allows for sampling at very, very fast rates. Enough that when you plot the signals versus time in Excel, you can see EVERYTHING that is going on. Here is an example of where I captured the manifold pressure, VTA signal, O2 sensor and the coolant temperature:

http://i303.photobucket.com/albums/n...ge/obdplot.jpg

Aaron

DanStew

Thanks for the reply Aaron, I was pondering between hijacking your thread or PMing you.

One question is, I am assuming you tried to do the PC route before making your own control unit. What stopped you? Or did you jsut want to tinker and make it from scratch?

Since my truck isn't throwing codes, it was just something to think about, and it actually bloomed from when i was going to megasquirt the motor in my old jeep, but once i sold that project off, i didnt think about it again.

ahickman

The pre-OBD vehicles do not have a diagnostic feature sufficient enough that would allow me to monitor the sensors at a fast enough rate. In addition, there would be significant reverse engineering needed to determine the protocol Toyota uses. PITA!

Also, it sounded like the on-board diagnostic was really limited in what info it could pass. Right away I decided to make my own board so I could do much more. Somewhere down the road I will decode tap into the MIL codes and display them as the two digit values as well as brief indicators of possible sources. I would use the Toyota FSM manual as an index. Just makes it easier for those of us that do a lot of trouble shooting on Toyotas. Ideally, this board can be moved from vehicle to vehicle just by unplugging.