Go Down

Topic: Reading OBD(1) data from Toyota Corrola 1992 .... (Read 4842 times) previous topic - next topic


Deeman

#31
Jun 04, 2015, 11:49 am Last Edit: Jun 18, 2015, 07:36 pm by Deeman
Well the first 4bits on my car is "0110"
When the care is first start I get this unique string : "101111111110000000000000000"
then every line of data starts with (16x1 + 0110) "11111111111111110110" then the rest of the 13 words data parts....
And on top of that, word-0 (zero) actually starts with a 1 bit not 0 bit like the rest of the words ... to make it a bit harder ;)
Is it the same on your car ?

Hi,
I think that the 1st word (0x00) longer then next. First 4 bits and the next 11 for "0x00 word" (in your PDF document about OBD-1 protocol) are car ID (may be model of toyota, or some vin number). For example in my car 0110 01010000011 = 110010100000 (without 1 start bit and 2 last stop bits) is not changed.

Some "unknown" values of words:

0x09 - Correction left (in Volts) in my car X=128 = 2,5V - standart and changes in interval 1,25-3,75 V (3V X=155)
0x10 - Correction right (not used in 4A-FE) may be used in any V engine

Flags (in addition to PDF):

0x11.1 - No (0) after 80 degre of Celsium
0x11.4 - detonation (0 = no)
0x11.5 - feedback (1=yes)
0x11.6 - extra enrichment (sorry for my English) (1=yes)
0x12.4 - fuel mixture left (1- rich, 0-poor) - lambda sensor
0x12.5 - fuel mixture right (not used, see 0x10)
0x12.7 - was always good (1), but after replacing high-voltage wires (maybe of other conditions) it always bad (0)...


In additional to your formulae:

0x01 I think, that scaling = X/8, if X=16, Injector pulse = 2ms

0x02 IGN, if connect E1 and TE2 to TE1 on diagnostic connector, you can see values, that correlate ~10 grad IGN (+-2), and ratio is about (X-65)/2=angle

0x03 angle of IAC, I see values more than 125, may be open status not equal 125.

0x05 ratio not equal 1:1, I think it about 3:2, for example X=40 --> p~26kPa, X=150 --> p~100kPa (in my car. in other this Value may be not MAP, but MAF or VAF).

Now I use PC and want to read this with arduino (but I have only 16x02 display without I2C and CAR_Reciver.ino not suite for me, and ToyotaOBD1_Reader.ino too...).

bebbo

Hi folks!

Thank you so much for all the work done! but I'm pretty noob on elctronics, decent on coding tho :) Can you please tell me what/how to connect the 4n35 to the 2n2222... and to arduino? ...and... no resistors?

sorry for the lame question!

Thanks you so much :)
imagination is the only weapon in the war against reality

Deeman

#33
Jun 19, 2015, 05:57 am Last Edit: Jun 19, 2015, 05:58 am by Deeman
Hi folks!

Thank you so much for all the work done! but I'm pretty noob on elctronics, decent on coding tho :) Can you please tell me what/how to connect the 4n35 to the 2n2222... and to arduino? ...and... no resistors?

sorry for the lame question!

Thanks you so much :)
With resistors, ofcourse.
Try to connect directly without optocouple or see examples in datasheet of 4n35 and your 2n222 (or any other amplifier). I measured signal with oscilloscope and detect stable 5V impuls signal with 10ms lenght of imulses from diagnostic connector.

mjwillia

Hi Guys,  just wondering if the GM ALDL 160 interface would work for this?
GM use a 160 baud 12v serial protocol.  The most basic interface uses a transistor as level shifter, and more complex versions use a max232.

Is there any reason why this won't work?

Thanks!  Oh FYI...  I had NO IDEA Toyota even had a serial out!

Deeman

Hi Guys,  just wondering if the GM ALDL 160 interface would work for this?
GM use a 160 baud 12v serial protocol.  The most basic interface uses a transistor as level shifter, and more complex versions use a max232.

Is there any reason why this won't work?

Thanks!  Oh FYI...  I had NO IDEA Toyota even had a serial out!
Try to use optocouple if you want to connect to ardduino. Using max232 or pl2303 not very difficult. You can use data-cable of old mobile telephones for example.

_Arduino_Programmer

Hello talofer99,

Thanks for creating this thread, and very nice job getting your project working with the help from GadgetFreak and others! :)

I would like to play around with this on my Toyota Celsior - unfortunately, I'm not the best with electronics either. I'm afraid to short out my Arduino board with the 12V supplied from the OBD-I port.

Would you be willing to list the parts you used, as well as share a circuit diagram? I realize it's been a while since you last wrote in this thread, but it would be very much appreciated!

Go Up
 


Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

Arduino
via Egeo 16
Torino, 10131
Italy