odb2.. reprogram ECU?

**mutilator** · 07-06-2004, 02:25 PM

i figred ODB2 was a 1 way thing, you request and read information, and couldnt change anything in the ecu etc... but i seen "one click" performance chips for the mini (and i assume other cars) that only use the odb port.

tom.

**god_of_cpu** · 07-06-2004, 02:47 PM

The port that OBD II uses on your car is not just a OBD II port. It a diagnostic port. Most of the OBD II protocols only use a couple of the wires found on the port, the others are normally used for proprietary communications depending on the type of car you have. For example, my infiniti also supports the nissan consult protocol on the diagnostic port, which if you have 2 grand or so to spend on the tool, you can use the port to program all sorts of really cool things in the car like how long the headlights stay on after the car is shut off, whether 1 door or both doors unlock on a single press of the keyfob, or even mess with the fuel mappings.

OBD II only supports one way communiations for the most part. The only exception to this is that you can send a clear trouble codes command using the OBD II protocol to clear all recorded trouble codes and reset the ECU. There are no other commands supported by OBD II that send data to the car. The only available tools that will allow you to mess with changing things in your car through the diagnostic port are proprietary.

**mutilator** · 07-06-2004, 02:48 PM

oh ok.

cheers

**DavidL** · 07-07-2004, 01:07 AM

The feds now require OEMs to comply with J2534 or "pass through programming". What this is, is a standard "black box" design that can be used to flash reprogram all vehicles that the reg covers. The flash files can be downloaded from the OEMs websites or via CD distribution ("reasonable fee"). If someone were really "smart", they could modify the flash file with other parameters to "hop up" the standard configuration (like more advance, more mph on the speed governor, etc).

**brandon** · 07-07-2004, 01:13 AM

Is it just me or does ODB2 sound like a member of the Wu Tang Clan?

**snoop** · 08-04-2004, 03:26 PM

theoreticly, couldnt the police check your ecu to gather how fast you were going before a car acident instead of looking a skid marks and what not.

**god_of_cpu** · 08-04-2004, 03:46 PM

Originally Posted by snoop

theoreticly, couldnt the police check your ecu to gather how fast you were going before a car acident instead of looking a skid marks and what not.

Only if the ECU recorded it and there is no reason to record it, at least not for long term (after the car is switched off) so no.

Also, this information would be proprietary and would require a specific method to extract it from each car. You can rest assured that the government would not have the capabilities to do this. Until there is a standard that all cars must comply to, to record this "black box" information, you don't have to worry about someone finding out how fast you were going.

**heypachuco** · 08-04-2004, 04:00 PM

http://www.policeone.com/policeone/f..._news&id=68451

**DavidL** · 08-04-2004, 06:40 PM

"Also, this information would be proprietary and would require a specific method to extract it from each car. You can rest assured that the government would not have the capabilities to do this. Until there is a standard that all cars must comply to, to record this "black box" information, you don't have to worry about someone finding out how fast you were going."

I think the government can afford an OEM scan tool - don't you?
They already buy a ton of them already. They own vehicles and service them too!

The issue is really over rights, not technology. The technology has been available for many, many years. Nothing new.
Does the data belong to the owner of the vehicle? There have been test cases and some have been won this way.
Does the data belong to the driver of the vehicle? Might be different than owner...
Can the government subpoena the data? Do they need a warrant?
Test cases on these issues are going on and will continue.

**Zoltan** · 08-05-2004, 07:12 AM

Good discussion going on here. Actually this goes on quite a bit with something called

"event data recorders" that are preinstalled in a lot more cars than you'd expect. They were originally designed to gather air bag performance data. But they've been used in court cases.

Here's some good information including a pretty informative video:
Harris Technical

Cheers!