ajderzie

Enough talk about the omnipresent EDR. Let's come up with some possible solutions. For those that are unaware, an EDR or event data recorder records the last 5 seconds of data from your car prior to a crash. This is otherwise known as a "black box." It is starting to be used by police, insurance compainies, and the courts. I personally don't have a problem with it as long as it is accurate and only used by the authorities and not by insurance companies. We each own our own EDR so the "ethical issues" are less relevant, in my opinion, than owning a radar detector. Once the EDR is manufactured, there is no way to check its calibration or question its accuracy. I'm sure it's correct almost all the time but I'm not so sure I like the idea. Regardless, I do not want this post to be a debate on the issues of EDR but rather a more technical discussion of possible bypasses. If you have an ethical issue with EDR tampering then please start another post and I will be more than happy to contribute.

For starters, I see two possible solutions. One would be to replace the module with a non-recording module that would still allow the airbags to function. Another would be to have an "Interceptor" similar to some electronic fuel injection module add ons. This would possibly change some or all of the paramaters using an algorithm.

Please chime in for other solutions. Hopefully someone here might know how to build a prototype or at least get us pointed in the right direction. Evidently, the modules are no longer encrypted and will soon have standardized formats across car makes.

ajderzie

As of now there are no legal issues to tampering with it as long as it was not tampered with after an accident and is wanted as evidence. Modifying it or completely removing it are legal but removing it would disable the airbags. Both the recorder and the data legally belong to the owner of the car. If an insurance company totals your car then they become the legal owner. If they then sell it to a salvage yard, then the salvage yard owns the recorder and the data.

2KFRC5

How do you what Cozmo is going to ask?

Cozmo

It's a warp in the space/time continium!!

2KFRC5

The Flux capacitor has gone wacky. You're not going to ask the question for another 25 minutes or so.

ajderzie

It's a gift....

Cozmo

Are there legal issues with tampering with the "black box"?

ajderzie

I thought this might be a good topic but I guess there is less interest than I originally envisioned.

Ok, does anyone know if the ABS will work when the module is removed and replaced with a simple jumper cable?

Rogue Leader

I would doubt removal would be that simple. I bet you would need some sort of "simulator" to keep everything working.

Just a thought but if you were to make and install such a simulator and get yourself into a situation where the EDR could save or lock you up and in its place they find the simulator which has only one purpose (cause it aint for performance), dont you think that would make you look guilty? I'm sure it would not help your cause.

bioman

If this was seen as part of the "safety system"...I don't think your insurance company is going to be happy with you if you have an accident that would allow them or police to check it. The police could certainly use "probable cause" as a reason to read it if you were in an accident that speed was a consideration. Mostly it's disconnection/absence would set up a guilty unless proven innocent scenario

ajderzie

Currently, there is no law requiring you to have a data logger in your car thus it is not illegal to remove it or modify it. I think it would be a stretch for a lack of data from the recorder, legally removed or modified, to be used against you. It would also have to be established that you knowingly modified it with the purpose of committing a crime as opposed keeping information that you own private. What would happen if you bought a car missing the data recorder? Would the addition of a roll bar or a supercharger also implicate you as a reckless speeder?

The reason it is all over the news is that people don't like this intrusion into their life, even with spotless driving records (such as mine). The data recorder is not open to inspection, debate, or independent confirmation at anytime after it has been installed. Is there any data on accuracy or malfuntions. Please don't tell me that there aren't any. I would find that very hard to believe.

I was hoping that people be interested in the intellectual challenge of reversing this. If not I wonder how many people would be willing to remove the data recording function by whatever means assuming it is completely legal. Maybe we should take a poll?

tiojames

I think there would be if you have to disconnect the air bag deployment system to keep the data from being recorded. The insurance company would probably have a say if you or passenger were severely injured or killed and they are financially liable. Not an attorney so don't know for sure. Certainly a gray area.

ajderzie

The goal here is to be able to disconnect the black box WITHOUT interfering with the airbag system. Any ideas?

BlackZ06

Sorry ... double post ... see below

BlackZ06

Yeah, here's an idea .... FORGET IT !!!!

If it helps to understand, the SDM is BOTH a black box (or EDR as you call it) and the device that controls the entire Airbag system.

The SDM isn't a "dumb" device, it is a microprocessor with memory (which is where the 5 seconds of data, plus lots of other stuff is also stored) and also systems such as a 23 Volt Loop Reserve (VLR) that is used to provide the electrical power to detonate the air bags should battery voltage be lost during the crash event and an accelerometer to measure vehicle speed changes. The SDM is wired into various vehicle systems, and as part of its on-going internal diagnostics checks to be sure it is receiving the following data .....

Quoted from the Vetronix website:

http://www.vetronix.com/aftermarket/

======================================== ==========

Q: Where does the air bag module (SDM) collect its data?

A: All SDM recorded data is measured, calculated, and stored internally, except for the following:

Vehicle Speed, Engine Speed, and Percent Throttle data is transmitted once a second by the Powertrain Control Module (PCM) via the Class 2 data link, to the SDM.

Brake Switch Circuit Status data is transmitted, once a second by either the ABS module or the PCM via the Class 2 data link, to the SDM.

Depending on vehicle option content, the Brake Switch Circuit Status data may not be available.

In most cases, the Driver's Belt Switch Circuit is wired directly to the SDM.

In some vehicles, the Driver's Belt Switch Circuit Status data is transmitted from the Body Control Module (BCM), via the Class 2 data link, to the SDM.

The Passenger Front Air Bag Suppression Switch Circuit is wired directly to the SDM.

======================================== ===========

If this data isn't available to the SDM, it throws a DTC, turns on the AirBag light, and ... well .... you have no airbags.

So, to build a bypass all you need to do is find an appropriate microprocessor, write all the appropriate software for diagnosing the entire restraint system, figure out the interface to the Class 2 data bus (so you can at least turn on/off the Airbag light in the instrument panel and respond to health checks from the PCM) ... write the algorithms to decide when to fire or not fire the bags ... oh and put that VLR circuitry and accelerometer in there too.

Let me know when you've completed this little task ... probably only took GM a couple of years and a couple of dozen hardware/software engineers to do this ....

ajderzie

Too soon to call it quits but you do bring up some good points. What would happen if you bought a new CDR module and removed the EEPROM which the crash data is permanently written to? If this is the only function of the memory chip then removing it or replacing it with a different chip may not have any effect. I am looking into this.

Any other ideas?

C5naples

Having the black box in my car does not bother me at all.

b98

It's not as hard to do as you think.

NAVY08

I hear that if you drive with one that has been through a crash it resets, you may be able to get one out of a wreck and keep it as a spair, then swich it before you ever get asked about it in the event of a collision. just a thought

ajderzie

Response to another persons question on another forum:

I just happen to design airbag modules (Not for Delphi - Probably the
manufacturer of your SDM) and have a couple of comments:
1) Don't be so sure that it is an external EEPROM IC

2) EEPROM is used for more than event recording. It typically holds
calibration info, etc which is needed to make the module function

3) Simply removing an IC WILL be detectable and would be considered internal
fault and make the module non-operational

I would buy another module and have it ready to be swapped out if needed.
However, this is not fool proof...

Having a functional module is worth the risks.