tuner vs scanner
tuner vs scanner I thought i posted this yesterday but i guess not.
I was wondering what the reason was why a scanner can only scan but a tuner can actually rewrite the ECU software. Both apparently operate on the same protocol , so both should have the ability mechanically to do the job. Is it just programming of the firmware in the unit or in the case of OBD2 links to computers, a software limitation?
I ask because I have a bluetooth obd2 scanner that I use with my phone to display various obd2 data and such. It would be really cool if a company like hptuners or efi-live had a little android app or so that would let you do what basically handheld tuners do.
I was wondering what the reason was why a scanner can only scan but a tuner can actually rewrite the ECU software. Both apparently operate on the same protocol , so both should have the ability mechanically to do the job. Is it just programming of the firmware in the unit or in the case of OBD2 links to computers, a software limitation?
I ask because I have a bluetooth obd2 scanner that I use with my phone to display various obd2 data and such. It would be really cool if a company like hptuners or efi-live had a little android app or so that would let you do what basically handheld tuners do.
except it doesn't answer anything i was asking.
They both talk to the ECU in the same protocol, they should then both have the ability to send all the same commands, it is just a matter of if the limitation on those commands are firmware driven in the obd2 device or software driven in the case of obd2 devices that connect to computers.
I know most are built differently to handle teh different common uses of them, but i was wondering what specifically keeps a scanner that is controlled by a computer from becoming a tuner controlled by a computer (assuming the software existed that recognized the adapter).
They both talk to the ECU in the same protocol, they should then both have the ability to send all the same commands, it is just a matter of if the limitation on those commands are firmware driven in the obd2 device or software driven in the case of obd2 devices that connect to computers.
I know most are built differently to handle teh different common uses of them, but i was wondering what specifically keeps a scanner that is controlled by a computer from becoming a tuner controlled by a computer (assuming the software existed that recognized the adapter).
I am not the one that is smart enough to give you the details but if you could talk to some of the people working on on a open source tuning solution 8-9 years ago you would better understand there is so much more involved in tuning or editing a calibration.
A scanner only reads the data stream and/or sends a command string(the question) and reads the return(the answer) or vice versa from the ecm. The tuning software and hardware has to unlock, download, erase, upload or install the new calibration while all the time avoiding any hick-up or glitch that will leave you with a dead ecm.
If someone has the old Hptuner forum posts saved or some other forums that work on that stuff that you could read i think it would help.
Edit: I guess you could start here... http://forums.openecu.org/
A scanner only reads the data stream and/or sends a command string(the question) and reads the return(the answer) or vice versa from the ecm. The tuning software and hardware has to unlock, download, erase, upload or install the new calibration while all the time avoiding any hick-up or glitch that will leave you with a dead ecm.
If someone has the old Hptuner forum posts saved or some other forums that work on that stuff that you could read i think it would help.
Edit: I guess you could start here... http://forums.openecu.org/
Last edited by DynoDR; May 1, 2011 at 12:53 PM.
OBDII data is pretty easy to get, it is federally mandated and available to anyone.
Reading the file from a PCM is not easy. You need to have the seed and key for the PCM, and be able to unlock it, then read the file. Assuming you can read it, the process of mapping that file out to where it makes sense is a bit of work, then editing it, and trying to get it back into the PCM without a bunch of checksum issues is a whole other ballgame.
If you look at the price of the scan tools vs. the price of tools with read/write ability, you'll start to see its not that simple
Reading the file from a PCM is not easy. You need to have the seed and key for the PCM, and be able to unlock it, then read the file. Assuming you can read it, the process of mapping that file out to where it makes sense is a bit of work, then editing it, and trying to get it back into the PCM without a bunch of checksum issues is a whole other ballgame.
If you look at the price of the scan tools vs. the price of tools with read/write ability, you'll start to see its not that simple
