Thread: Raspberry Pi - Virtual Sensors for Car Computers

funny, i was playing with a snap on scanner today, it can do all this turn stuff off/on make stuff work or not work.

Originally Posted by Scottydoggs

funny, i was playing with a snap on scanner today, it can do all this turn stuff off/on make stuff work or not work.

Winter before last on the 06, I was was fighting CEL, I forget the number off the top of my head. It was when the car first starts, it turns on a blower and opens a valve to dumps oxygen into the exhaust to check that the 02 are reacting. That motor only comes on for a few seconds, so my GM buddy brought home his gadget. While the car was off, we could command the blower on, open and close the valve and listen at the exhaust. All seemed OK. Then started the car and would do the same test, while watching the 02. All seemed ok. I replaced the valve as a shot gun fix, did not fix it. Then summer came and it quit throwing the code. So I waited this winter, still no code. I was suspecting the heater on the 02 is not functioning correctly, and once the car starts it works. Thats another thread, the point is this all can't be magic. The time and money I am spending on this is nothing compared to what I spent on college to learn, and this is a lot more fun. :-)

First step (Hello World of hardware), light a LED, well in this case one of the 12v lights from the donor car. Well, you can if you figure out how to turn on a ATX power supply without a motherboard. Google took me here. http://www.instructables.com/id/How-...-without-a-PC/
Here is what he said .....
Just look after the green wire in the cable tree from the PSU.
Follow it to the 20 or 24pin ATX plug.
The green cable is what enables motherboard to power up the PSU
Jumper the green wire on the ATX plug to any other BLACK wire. Best practice you should connect the green with black besides the green.

i got the same jumper in my old pc power supply lol

i really need to put a switch on that.

I found this on a forum. It also has a 99 so you can compare them.
Here is the on for 1997.
At the bottom, I give some real life pictures.

1997













First figuring out which is blue and clear, colors are actually into the socket, you can not see it just looking. Undoing the screw, pulling the plug you can view it. So next was getting the white piece off to see which way it is numbered. Unless I made a mistake the clear is upside down. Here are some pictures to explain.


If you turn so the writing is right side up, then blue is on top and clear is on bottom.

See, pin 1 on the blue is upper left, while pin 1 on the clear is lower right. I guess it make sense if you think from the center.

Also, getting the white covers off took some doing. Trying not to break it, finally I got a little more force and pry up as close to the pin as possible, then just walked around carefully. Looks like you could press them in, but for some reason it did not work for me.

I was using my bluethoot ELM327, with "Torque Pro". All worked on my project car. Of course, I could start it and had readings.
For this test, I was getting "Could not connect to ODBII" and it would cycle connect to bluetooth, and then show the "no ODBII" error. It would just keep cycling.
I wonder if the PCM is even cable of responding.
Here is what I connected using the pinout below.
Power 19 Pink
Ground 60 Black
Now 59 was labeled as Class2 data. It also gave as one of it's symptoms, "No Scan Tool". Here whats weird, the color is Dk Gm, but it is purple. Now pin 2 on the ODBII connector is purple. Just to check my color and pin, 62 was Dk Gm/Wht. You can double check me from the pictures below.
Oh well, enough for today.....

Success!!!!


Well the coolant temperature looks like we are in in ADecker's state, 27" of vacuum, but hey there is some green. :-) Now can I manipulate the sensors with the Pi to fake some reading.
The coolant may be a good one to start with.
Notes when it's time...
Coolant Temperature Sensor (CTS)
°F °C OHMS
210 100 185
160 70 450
100 38 1,800
70 20 3,400
40 4 7,500
20 -7 13,500
0 -18 25,000
-40 -40 100,700
I have some parts on order, but being cheap I went with ebay from China. May be awhile. Next need to find the pinout for the BCM. Then maybe use the donner PC box to mount some of this. Will see.




Now the $64 question....

What was my problem? Not sure if I want to share, rookie mistake.
First, thanks Scottydoggs. Your post http://www.grandprixforums.net/threa...=1#post1270142 got me off in the right direction.

Clue as to what it is, look at the bulb on top and the one on bottom. When I got the "hello world" light, to light up I thought it was kind of dim. Guess why, yep I was using the 5v wire. :-(