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OBD-II info storage limits

eodmule

By eodmule
in Ask A GM Technician

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eodmule New Member

eodmule

Posted
Posted

A co-worker of mine said that his dealer told him GM 's computer could store all data that was inputed into it for the life of the vehicle. Is that possible? I thought the computers stored the last 30 seconds of data, not all the data for the life of the truck? If it could, a person could make an interface and plug it in and download and access the entire history of the vehicle. Everything from driving habits of all the previous owners to its service history. It would make stuff like Carfax obsolete. Has anyone heard of this?

GM-Tech Senior Enthusiast

GM-Tech

Posted
Posted

Never heard of such a thing and I see no good reason why they would want to store all that information. Plus, I don't believe it would be possible even if they wanted to if you think about it.

 

Do you realize how much data passes through the computer? When I do a snapshot, which consists of just a minute or two of data, it's several thousand bytes of data. Can you imagine what that would add up to over the thousands of HOURS your vehicle is running? The thing would need more storage memory than I can even imagine.

bobcat5544 Enthusiast

bobcat5544

Posted
Posted

it's like a black box, but not many veh have it, except newer cars. the data that is stores only takes about 1mb for every 10,000 hours the key is in the on position.

 

yes it can store the life of the veh since most will go 15-20 years and that is pushing it

 

10,000 hour is average per year you spend in you car

 

remind you the is a ruff estiment

redvett Senior Enthusiast

redvett

Posted
Posted
A co-worker of mine said that his dealer told him GM 's computer could store all data that was inputed into it for the life of the vehicle. Is that possible? I thought the computers stored the last 30 seconds of data, not all the data for the life of the truck? If it could, a person could make an interface and plug it in and download and access the entire history of the vehicle. Everything from driving habits of all the previous owners to its service history. It would make stuff like Carfax obsolete. Has anyone heard of this?

 

 

 

 

The SDM only records less than a second or so of data from a crash when the air bags are deployed. It records speed,throttle position,brakes on or off & seatbelt usage. In event of a deployment its permanent. On the other hand the PCM OBD-2 records powertrain data for faults and operation necessary for operation. No driver conduct is collected.

Service history is only collected by your GM dealer when you bring it in for service.

GM-Tech Senior Enthusiast

GM-Tech

Posted
Posted
it's like a black box, but not many veh have it, except newer cars. the data that is stores only takes about 1mb for every 10,000 hours the key is in the on position.

 

yes it can store the life of the veh since most will go 15-20 years and that is pushing it

 

10,000 hour is average per year you spend in you car 

 

remind you the is a ruff estiment

 

 

 

 

If it stored only ONE BYTE every second, that would be roughly 36 mb in 10,000 hours (36 million seconds = 10000 hours). One byte of data doesn't contain a whole lot of information, so what could 1 mb contain. Squat, that's what. :P

 

I don't know where you're getting this information but I think it must be from some conspiracy theorist. :P

GM-Tech Senior Enthusiast

GM-Tech

Posted
Posted
The SDM only records less than a second or so of data from a crash when the air bags are deployed. It records speed,throttle position,brakes on or off & seatbelt usage. In event of a deployment its permanent. On the other hand the PCM OBD-2 records powertrain data for faults and operation necessary for operation. No driver conduct is collected.

Service history is only collected by your GM dealer when you bring it in for service.

 

I think we're probably wasting our time trying to convince some people that GM really has better things to do than try to record every single parameter of their vehicle for its entire life.

redvett Senior Enthusiast

redvett

Posted
Posted

 

 

I think we're probably wasting our time trying to convince some people that GM really has better things to do than try to record every single parameter of their vehicle for its entire life.

 

 

 

 

 

GM-Tech your so right. We could talk about this for years and people would be convinced that everything they do while driving is being recorded.

redvett Senior Enthusiast

redvett

Posted
Posted
So, GM may see that I speed...all the time.  Tell me and the cop at my window something we don't know!  :P

 

 

 

 

GM or anybody else cannot tell if you speed. Only if you have an accident and your airbag goes off then if there are deaths and the police get a cort order they can access the info.

Read the earlier posts.

eodmule New Member

eodmule

Posted
  • Author
Posted

I told him that to store that much information it would be quite the undertaking. Why would they (GM) even want that info anyway. ODB-II store all relevant error info so what would be the need. I think he's just a little paranoid.

redvett Senior Enthusiast

redvett

Posted
Posted
I told him that to store that much information it would be quite the undertaking. Why would they (GM) even want that info anyway. ODB-II store all relevant error info so what would be the need. I think he's just a little paranoid.

 

 

 

 

Tell him dont worry abot the Auto MFR's worry about a navigation system or GPS watching his speed. Some car rentials use it and soon your insurance companies will require it.

redvett Senior Enthusiast

redvett

Posted
Posted
Redvett...I know they can't see that I speed, I was just poking some fun into the conversation.  Sorry about that.

 

 

 

 

tomrex

There are a lot of people that think that the auto MFR's really want to watch us and thats the last thing they worry about. Emissions are there priority since they have to pass every model every year.

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