Who's good at diagnostics? What does my computer know?

I am trying to learn a little more about what data is generally available through the OBDII port in real time, as well as what is stored and can be accessed with good diagnostics tools.

I'm not too interested in the extremes- yeah, I know a top end AMG records my pulse rate and blood type, and that big brother wants to enslave my children.

I know the computer handles engine management data, but how about driving patterns? Service intervals? Speed? Cornering G's? GPS coordinates?

Does it store engine management data? (For example, could you graph historical engine operating temps?)

I'm not really interested in the potential, I am more interested in the averages, or the typical.

What routine maintenance items can now be measured and tracked through the average OEM computer, and accessed without dealer certified technicians and equipment?

For starters, basically any number the car has a sending unit to measure can be seen by a mere mortal with an iPhone and a $7 dongle.

OBD2 is a rather crude standard that only handles data from the engine sensors (and the VSS sensor - the closest thing to any kind of driving data it stores). It doesn't store anything long-term, disconnect the battery and all is forgotten. An OBD2-compliant ECU is not aware of GPS position, time of day, how long it's been powered on...we're talking consumer-level early-90s technology that wasn't even ambitious for its time.

And yes a smartphone with a wireless OBD2 adapter will show you everything. An iPhone in particular is not a good choice though due to the way iOS limits Bluetooth communications.

In reply to GameboyRMH:

Before one gets too harsh in thinking of what OBDII is capable of, remember what the intention is- On Board Diagnostics. Not performance, not where you are, not anything like that- it's there to determine if an emissions system fails, why, and some info to help figure out the root cause. That's it.

There is a memory- but it's triggered if a MIL code is set. So that the tech can see what the car was doing when the light was turned on.

For sure, it's not something that OEM's want to use to share a ton of data on how the powertrain is being controlled, and even more that that control can be altered (which is against the law).

Once one realizes that, you may have a better understanding of what and why you see what you see.

In reply to alfadriver:

Which part is against the law?

Altering the car or the controlling device, modifying the proprietary software, or changing the way in which it is controlled?

If it's the later, it seems like a lot of us would be stepping over the line with MegaSquirt, etc.

In reply to SVreX: Better yet would be all the people mucking about with GM ECUs and posting videos on YouTube.

In reply to SVreX:

Yes. It would all be tampering.

Legally, MS is an off road device only. It's incredibly unlikely that any person will be investigated, though. Companies, on the other hand....

(I have told that to a few people, to change the language that they sell products for)

Basically it's against the law to make anything that can cheat an OBD2-based emissions test. MS is not OBD2-compliant, so not illegal, but it could make your car fail emissions because of this.

FWIW, this is the law I'm talking about http://www.gpo.gov/fdsys/pkg/USCODE-2010-title42/html/USCODE-2010-title42-chap85-subchapII-partA-sec7522.htm

(a)(3).

removing and replacing the ECU does count as not legal. MS is not legal, Gameboy. But it can be an off road device.

Back on topic...

Ok, let me ask my question differently.

Since some (many? Most?) cars are data logging additional info beyond a basic OBDII, what is generally there, and how can it be accessed?

For example, I know many cars record average speed over lifetime and hours engine running.

I am talking read-only. Nothing illegal.

SVreX wrote: Back on topic... Ok, let me ask my question differently. Since some (many? Most?) cars are data logging additional info beyond a basic OBDII, what is generally there, and how can it be accessed? For example, I know many cars record average speed over lifetime and hours engine running. I am talking read-only. Nothing illegal.

Most factory cars, even today DO NOT log anything beyond basic OBD2, unless they have OnStar. I know OnStar data is uploaded to OnStar's servers, I don't know what's stored locally on that. Some navigations systems keep recent locations stored on the device itself, how to access it depends on what device we're talking about, but you shouldn't expect it to be easy.

If you have an insurance company black box in your car, they log GPS and accelerometer data (onboard the device itself) which gives them most everything they need, some also log OBD2 data.

The cars that do log extra stuff from the factory all use proprietary access protocols, usually over serial comms. It's a proprietary data file accessed over TCP/IP via Ethernet (or cellular data) in the case of the Tesla S.

My truck has an hour meter from the factory, so it's recording something long term.
You also have to remember there are a LOT of things that you can see/record real time thought the port that aren't part of the OBDII protocol. On my 2 I could read pretty much every engine parameter, individual wheel speed sensors, individual wheel ABS events, brake pressure, factory yaw sensors and more. This was with and AIM Solo. Other cars could also read steering angle and pretty much everything else. New cars have a LOT of things being measured for TC/ABS/stability control. It's pretty cool.

In reply to Gameboy RMH:

Like mazdeuce, every truck I've seen since about 2000 had an hour meter and lifetime average speed integrated into the digital speedo. Same thing with my 2013 Hyundai. Your car might know more about you than you realize.

Mazdeuce: What's an AIM Solo?

Keep in mind the hour meter/average speed may be a feature of the instrument cluster and not accessible in any other way.

SVreX wrote: Back on topic... Ok, let me ask my question differently. Since some (many? Most?) cars are data logging additional info beyond a basic OBDII, what is generally there, and how can it be accessed?

Which ones log more than OBDII? As it turns out, we are looking for those kinds of tools, too.

Was that a thinly veiled threat??

SVreX wrote: Was that a thinly veiled threat??

No, the second part of my answer was real. We are looking for OBD tools.

I'm sorry that I had to burst bubbles about legal items, but that's the way it is.

AIM SoloDL
The software is free to download from AIM so you can take a peek at what is available for the different cars it supports. I ran the package for an RX8 (I think) and it grabbed just about everything perfectly on my 2. I need to get it back from my friend to see what I can pull off the Cadillac.

Ok. I'm a little confused.

With the power of Ford behind you, can't you guys pretty much come up with whatever OBD tools you want??

SVreX wrote: Ok. I'm a little confused. With the power of Ford behind you, can't you guys pretty much come up with whatever OBD tools you want??

We actually realize that more than Ford makes cars. May be stunning, but true.

Plus some of the tools we have are not that easy to use.

Maybe it's easier to realize that the work I do does not go through the OBD system. It uses real development hardware. That way we can monitor all +100,000 things that are in the ECU.

Well, my question was WHAT info is available, and most of you seem to be answering HOW to access it.

I am first interested in the WHAT. Standard OBDII PIDs are more than adequate for what I am thinking, but most of you seem to be saying that most standard PIDs (SAE J1979) aren't accessible. There is a heck of a lot more in the standard PIDs than engine temp and throttle position. Is the data accessible, or not really?

Alter that, the HOW. Are there better ways than the OBDII port to access whatever data is accessible?

In reply to SVreX:

Should be. I took one of our old tools that does not have data logging, pluged it into my Miata, and saw the PIDs all there to read. Short term fuel trim, long term fuel trim, spark advance, etc. All there for anyone to see. If I had a logger, I would have recorded it.

Seemed like some are posting that more can be gotten.

Wheel speed, brake pressure, abs events, yaw and both G sesnsors were available on the 2 as well as every engine parameter that I could think of. The program I was running was for the RX8 and also had steering angle which my car did not have.
On my truck you can also see the full ABS computer stuff (sensor checks, codes, pressures and events) through the port with a better handheld than the typical smartphone/dongle pair.
I can't pull the lists of what can be read with the Solo without looking at the software which I'd need to fire up my Windows computer to do.

In reply to mazdeuce:

You reading all that through the OBDII?

Yes. 10-30Hz (maybe more? I didn't need better resolution than that so I set it pretty low). You can drown in data.