jeffas000073

If I were to leave a bluetooth OBD1 scanner adapter plugged into the ALDL port all the time, would it drain the battery?

Tuned Performance

iTrader: (92)

GeneralDisorder

iTrader: (1)

It won't run right unless you have the data-logger up and running on your android device, etc. Because of the 10k resistor being in the port it puts the engine into a weird mode where it will cause issue with cold idle, etc. For whatever reason those modes change the operating behavior for testing purposes and were not designed to be used in normal operation. It changes ignition timing, and GM manuals said it shouldn't be in that mode till the engine is at operating temp.....

Best advice is don't. I did that for a while on my Trans Am and found it caused strange behavior.

GD

jeffas000073

If I am actually running a data logger (Tunerpro RT in my case), how does the ECM know to run in a normal mode verses not running a datalogger and running in a 'weird' mode?

GeneralDisorder

iTrader: (1)

Two of the pins in the port are shorted together with a 10k ohm resistor. Or once it goes into communication mode it will change some aspects of the tune - idle speed and ignition timing change when in communication mode. It also will do oddball stuff like generate false knock events to "test" that subsystem..... It was never intended for anything but actual troubleshooting diagnostics at a dealer or engineering level so it's not really designed to allow a constant data-logger. If you want something like that you should look into Rbob's EBL system.

GD

Tuned Performance

iTrader: (92)

GeneralDisorder

iTrader: (1)

Yeah - that is true - and even then it depends on which speed you want the 165 ECM to communicate at I think. When I did this and left the adapter plugged in all the time it would idle higher than normal and it does do things like generate false knock, etc. I just wouldn't do it - invest in the EBL system and do it right. No it won't be bluetooth but really why the need to datalog all the time anyway?

GD

cardo0

I don't see any need to leave your scanner plugged in all the time. What are you trying to accomplish doing that? Maybe there's another way to do whatever your trying to do?

jeffas000073

No real necessity to keep it plugged in. I'm doing quite a bit of datalogging lately trying to track down a knock and was just getting sick of the usb cable always being in the way. At least the bluetooth would eliminate the cable to the computer.

cardo0

Well there are some OBD II devices that remain plugged into the ALDL port. It allows our big brother to keep track of how we drive our cars. I believe there are insurance discounts offered to use this.

Proposals exist to monitor your behavior in the car while driving let alone how you drive. And who watches what they do with that information? Do you really want a new car?

sofakingdom

iTrader: (1)

You're talking about establishing a conversation with a computer whose processor was introduced to the market in 1977. If i'm not mistaken it had 128 bytes - not gigabytes, not megabytes, not even kilobytes - BYTES - of RAM; 2k of on-board PROM (but of course capable of addressing external ROM, which contains the lookup tables and part of the opcode, and is what often is referred to as a "chip", with a capacity of 64k or less at first and as much as 256k later; and I believe a 1MHz instruction clock (although that doesn't mean it had 1M machine cycles per second, probably more like about 1/8 of that). The 165 might have had a later version (6809) with a built-in hardware multiplier and a few other improvements, but it was the same basic architecture. The 730 may have had some further incremental improvements but was still ... kinda crude by modern standards.

Do you remember what your smartphone looked like in 1977? or what the thing you were surfing the Net with in 1977 looked like?

The processor in our cars is taxed almost to its limit just doing the job of running the engine. It has almost no excess capacity left over to perform any other tasks, like spitting out data while simultaneously doing its normal tasks, without affecting those other tasks. If memory serves, the max data rate available out of that port, is something like 90 baud originally, and might have been as much as 300 later; of limited usefulness at best, given the long time intervals between "frames" of data.

You should temper your expectations.

But to answer your question, if the power supply you hook the interface to is battery, then yes it will drain the batt; if it's ignition, it won't, because it will get shut off with the key. Eeeeeeeezie enough to determine with your DMM.

cardo0

What computer are you talking about and who are you referring too? OP has an OBD I and I mentioned OBD II for an example as Consumer Reports published about that communication through this ALDL port with insurance companies on June 2018 (pg 46). Though I don't see why it couldn't be done with an OBD I computer as the collection and transmission of data is preformed by the adapter device and not the ECM. I don't see any point in what your trying to make other than those OBD I computers are terribly low performance compared to current ECM capabilities. Heck even the port connector was different - ALCL connector. But so what?

Drink more de-cafe.

sofakingdom

iTrader: (1)

Right...

But where does the data COME FROM? One way or another, the ECM has to spit it out before the "adapter" can "transmit" it. And THAT'S where the problem lies. The "adapter" can only "transmit" what data has been fed to it.

I have gigabit Ethernet in my house. My incoming cable connection is 20Mb on a really good day. Does that 1000 bit rate make any difference compared to 100, surfing the Net? Same principle trying to datalog. If the data SOURCE is low-speed, the "adapter" is STUCK at that rate; can't speed it up somehow. No matter what the shape of the connector is or what name it's called by.

I don't drink decaf.

Go drink some reality and common sense.

cardo0

Okay reality is my AutoXray scanner does realtime sensor/data display while I drive my OBD I camaro. Common sense tells me you are imagining again and really don't know what or how a scanner works.

GeneralDisorder

iTrader: (1)

Yeah but it's not really designed to do that at all times. It is supposed to be a diagnostic tool and GM engineers never envisioned a day when people would want to do this with this system. Their information packet rate is painfully slow and the more data lines you request the longer it takes between successive data packets. Making the data sometimes difficult to interpret as you miss critical events. Essentially the granularity for more than a couple of data lines is too large to tell more than a general picture.

It's useful - but I wouldn't want to just leave it running all the time - that's not all that useful compared to quality, modern gauges - many of which can also be datalogged and "streamed" into the OBD-I data stream. Such as with a wideband controller.

Ultimately having them in these live data modes does impact how the engine runs - diagnostic modes can alter idle speeds, create false knock events, and are contra-indicated in the service manual unless the engine is up to temp, and should only be used for diagnostics - not for normal driving.

GD

cardo0

Yeah that's called data aquisition and the sky is the limit today. Edelbrock even carried a DA unit in thier cataloge for a while. And for performance TESLA still sells the G-Tech though it doesn't measure any engine parameters other than RPM and calculates HP.

But like the OP said he is just using the blue tooth continuously for convenience and not trying to upgrade anything. I'd have to say DA is going off topic here.

sofakingdom

iTrader: (1)

Right: "today".

But with 70s / early 80s technology, the ceiling was ... quite a bit lower ... by the standards we've become accustomed to 40 yrs later, as far as the amount and speed the info could be extracted. "Technology today" doesn't somehow retroactively make a higher data rate available from the 70s silicon. Bluetooth, wi-fi, SAN, whatever; doesn't matter. It's all about what the OE ECM is capable of spitting out, with its 70s limitations.

I remember the first modem I ever used. It was about the size of a dishwasher, and had a place known as "acoustic coupler" that you could place the receiver of yerbasic industry-standard Western Electric handset, such that it had access to the "ear" and "mouth" of the physical phone to transmit data. That was 1973. We mostly used it to connect our DEC System 10 to a bunch of PDP-8s (for those of you who don't know, the PDP-8 was a minicomputer, that the first Intel MCU chip, the 8008, later emulated; a PC will run unmodified 8 code, but the 8 was only 8 bits internally, with 2 bytes for the memory address bus, allowing access to 64k of memory). The data rate was 110 baud. Most people had no forking idea you could transmit text over a phone line yet anyway. There were only a handful of phone #s we could dial up and communicate with, but I remember bringing one particular young female to see it, and utterly overwhelming her with the glimpse of the future. Ahhh, to be young again... youth is wasted on the young, they are too inexperienced to appreciate it.

However all that may be, "data logging" out of the stock ECM in our cars, is a painful experience when compared to 201x cars. Better than what we had before, in a way, if you have the specialty for doing it, but not near as rich a result as what we have now.

cardo0

Data rate? Hah! You overlooked the computer at the end - the mechanic (or wanna be). Beyond reading a code and looking it up the owner/mechanic degrades rapidly to buying and swapping parts. Not a lot of good reference material on OBD I but the book I have I'm on my second read and it takes some effort to digest and use what I've learned. I guess I'm trying so say its difficult to learn OBD I faster than I will forget it - but that's what it is. For the non-proficient like me it becomes a good reference when I need to use it. But for the full-time mechanic OBD I does have quite a lot of information even if at slow rate.

So that is what also is overlooked here as in the future we may see even smarter scanners/adapters with AI that will go that next step for any user. Even at a slow data rate the sensor information is there and a "smarter" scanner will replace the text books for diagnosis and help. And my assumption is any company manufacturing scanners that is not investing in AI is gonna be left behind in the market.

TAbracadabra

I totally understand what sofa is saying. I was right there in the '70s and '80s with computers.
A scanner does not read sensors or anything DIRECTLY on our cars. It has to have a "Conversation" with the ECM and request the data and then the ECM gets the data and sends it to the scanner using up valuable clock cycles and memory to do so. For EACH request!

This extra overhead can easily cause the ECM to fail in performing its needed tasks in a timely manner like reading sensors and adjusting spark timing and fuel injector pulse widths.

Just to add in case this additional information may be useful for any new reader of this thread.

All the best.