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Topic: Car computers? (Read 1506 times) previous topic - next topic

Car computers?

Could the Bus Pirate be used on car computers, like the engine/electronic control unit (ECU) and/or the powertrain control module (PCM)?

What about reading/communicating with the car's OBD-II port and data?

Re: Car computers?

Reply #1
Maybe, depending on the car and your experience with electronics. OBD-II covers a number of serial protocols, but data rates range from 5 baud up to 500,000 baud. You might be better off purchasing an OBD-II adapter, rather than trying to use the Bus Pirate for this.

Re: Car computers?

Reply #2
the OBD-2 connector commonly has 3 bi-directional serial line pairs(j1850 bus, can bus and iso 9141-2) seven pins for vendor options, battery power,chassis and signal grounds.

the vendor options may have additional serial lines eg: sensor networks or could be used to try to lock out non-manufacturer approved code readers. try getting a sub $500 reader to check your ABS or airbags.

there are more suited microcontrollers for this than what is provided on the buspirate, SiLabs, Atmel, and TI all have various options and some even have all three standard automotive buss interfaces built in.

i tore a code reader apart a few years ago http://http://dangerousprototypes.com/2011/03/01/a-look-inside-an-obd2-tool/, this is a stand alone unit, but starts to show what is involved in interfacing to the obd2 system.

 

Re: Car computers?

Reply #3
Thanks, guys.

I have an OBD2 reader, but I don't think it has access to the ECU and engine timings. How hard would it be to interface either the Bus Pirate or a modded OBD2 reader to access particular properties and settings beyond just car sensor data?

I don't have the finances to purchase expensive readers and programmers at the moment (beyond my BP and OBD2 bluetooth module), and so I'm just wondering about the feasibility of either a potential Bus Pirate route and/or a modded OBD2 programmer route.