I want to communicate to the ECU of a vehicle to display few information on an LCD. I want to interface through CAN. I'm thinking to use PIC microcontroller. Also I'm in privilage to program the ECU too. Can anyone suggest me a possible low cost implementation? Also please help me how to transmit and recieve information through CAN.
Unfortunately, it may not be as simple as implementing a CAN interface, the complexity of such a project depends largely on the make, model and year of the vehicle as well as the original import country in some cases.
While I have a considerable amount of experience with this issue, this is a complex topic which could easily fill several textbooks, discussing it in a venue such as this forum will be a challenge.
I should also state my experience is from the viewpoint of the US car market, as such the situation in your locale may differ.
However, as the US is one of the largest car markets, I suspect standards implemented in the US have had an impact globally.
To give you an idea of the challenges you face with such a project, consider events of the past couple of decades.
Automobiles were not mandated to utilize CAN (ISO 15765) until January 1, 2008, therefore automobiles manufactured before this date utilized a myriad of communication protocols.
These protocols are commonly referred to as pre-CAN, the three most commonly used were as follows:
SAE J1850 PWM - Utilized primarily by Ford
SAE J1850 VPW - Utilized primarily by General Motors
ISO 9141-2 - Utilized by Chrysler, European and many Asian Imports
Fortunately, another standard, On-Board Diagnostic II (OBD-II), mandated the use of the OBD-II interface for all automobiles manufactured after January 1, 1996.
The OBD-II connector (J1962) provides 16-pins for standardized access to the above three protocols, a fourth ISO 14230 KWP2000, and of course CAN (ISO 15765).
The European Union implemented their own version, EOBD, and mandated its use for gasoline vehicles manufactured in 2001 and diesel vehicles in 2004.
The Japanese have also implemented their own version, JOBD.
Now considering the lifespan of an average automobile, the fact is, most vehicles on the road today do not utilize the CAN (ISO 15765) protocol, but one of the other three communication protocols listed above or a fifth protocol, ISO 14230 KWP2000.
However, there are several alternatives to designing and building an OBD analyzer for use with the majority of automobiles in service today.
Anyway, hopefully this sheds some light of the subject and I will be more than happy to advise you as to your options.
BigDog