SAE J1978 OBD II Question... - Page 1
Forum section: electronics / beginners

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 20, 2012, 09:33:23 pm
content: why do i have to pay for the standard?USD66 herehttp://standards.sae.org/j2201_199907/

author: Baliszoft
author_rank: Frequent Contributor
timestamp: December 20, 2012, 09:38:27 pm
content: I already spent a fortune on sae papers. This is how it works.

author: Kremmen
author_rank: Super Contributor
timestamp: December 20, 2012, 09:45:46 pm
content: Quote from: Mechatrommer on December 20, 2012, 09:33:23 pmBecause the people working for the standards institute also have to eat. You should understand that standard bodies are not charity organizations or public services, except in rare cases. The added value the standards bring is worth money to commercial implementors because a successful standard ensures compatibility and makes design easier since many things have been worked out already in the standard.That is the glass half full view. The half empty view is that there are standards worse than useless, not worth the paper they are printed on. But hey, it is a free world, it is not stupid to ask a price, but it might be sometimes, to pay it.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 20, 2012, 10:13:32 pm
content: because first its only for personal use probably diagnosing my own car if i ever get around it (programming some PIC with the standard or such). if i cannot realize it then USD66 is just wasted down the drain. second, USB standard is free? soi think automotive industy is still not up to the "open source" terminology? maybe i should just buy some cheapo scanner with some err code descriptions, hmm.

author: Kremmen
author_rank: Super Contributor
timestamp: December 20, 2012, 10:43:23 pm
content: Sure, but whether you are able or not to implement a design is fully your problem, that is no business incentive for anyone selling the standard documents for profit.And yes, some standards are free, but never those created by recognized standards organizations such as ISO, IEC, ANSI, whatever.You may be better off just shelling out the cash for a functional OBD reader instead of a standard paper telling you how parts of it were implemented. Depends on what you are aiming for. If you want to fix your car, just buy the gadget.

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: December 21, 2012, 04:09:11 am
content: Quote from: Kremmen on December 20, 2012, 10:43:23 pmThat was exactly my conclusion. You can get a STN1110 OBD II to serial converter (I think it is nothing but a pre-programmed PIC) for $9.99 U.S. from ScanTool.net.Yet another project on my to do list (sigh)

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 21, 2012, 12:16:13 pm
content: yeap making the reader/scanner can be another thing, let alone that, finding the adapter that fit in is one thing... my intention is i want to be able to send request code and decode the reply code.any suggestion of a device that can do this? ie console like or manual typing the code out, and read the raw code in? i dont mind if its PC based OBD to USB converter with good software (i can bring my laptop into the car). better if the device is "fully automated single click scan fully 100% OBD II codes compliant"? at bang per buck price?and then some device i saw in ebay is only for OBD2 Audi, some can support all some can support some models which bugs me its like different car model uses different OBD2 standard or codeset?

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: December 21, 2012, 12:54:04 pm
content: @Mecha:I haven't started this project yet, all I want is a device to read ford trouble codes and realtime mpg (I have a 2008 ford ranger). This is a very low priority project for me. Last time I searched I found that all the cheap dongles are based on the ELM327 chip or its successor the STN1110 and that each car manufacturer diverges from OBD2 with their own proprietary add on codes and formatsThere are some open source software projects which run on PCs to drive and interpret the codes from an STN1110. I think STN1110 command set resembles the old AT (Hayes modem and compatible) commands on the serial side. Note that car manufactures don't release all of their codes so that people have to go to official dealers to get their cars repaired. So even if you buy an official standard you still need a separate negotiation with the car company(s) of interest to pry out all the documentation on a specific vehicle. (fscking shitbags). There was an attempt some years past in either Canada or US - I forget which, to pass legislation to force the car companies so that independent garages could scan for all codes on all vehicles, and it died unpassed.I stopped my investigations last year some time ago because I was too busy with other stuff, sorry I am not much help. You are going to have some googling ahead I'm afraid.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 21, 2012, 04:19:26 pm
content: Quote from: chickenHeadKnob on December 21, 2012, 12:54:04 pmyou summarized it pretty well, now on to do other stuffi dont have to go to the dead end as you did. last time my car got repaired there was a touchscreen like device with every manufaturer symbols on it to click in as startup screen menu. so i believe each manufacturer uses "their proprietary" the same codeset throughout their car models. whether toyota prius or camry or corolla they all same codeset i believe. now after i paid $66 for the standard "basic" OBD2 from SAE, then later i'll have to go to toyota or ford et al to pay or bribe a fortune to get their own extension, right! no thanks.

author: ciccio
author_rank: Frequent Contributor
timestamp: December 21, 2012, 07:50:35 pm
content: I clearly understand the point about having to pay for a copy of a standard when this will lead you to design or manufacture a product, but the Italian legislators have come to the point that:1) By LAW I must measure the acoustic insulation of ceilings from impact sound using a tapping machine and a sound level meter according to UNI EN 12354-2 standard.2) Oblige me me to pay 200 euros for a copy of the standard.For me this is like putting a road sign saying:a) there is a speed limitb) stop and pay a sum to the policeman to know it.The first Italian law about electrical produt safety (circa 1980) wrote:a) Electrical products must be manufactured according to the state of the art (omissis..)b) the state of the art is defined by UNI standards.Why not BS standards? Why no Chinese standards?Technical standards are the product of organization that operate in a monopoly condition.Most of the times they are funded using public money.If I'm obliged to respect the standards, the standards must be in the public domain. Point.Merry Christmas to all

author: Fraser
author_rank: Super Contributor
timestamp: December 21, 2012, 08:27:07 pm
content: I have purchased several cheap OBDII scanners for my cards....a Nissan X-Trail and an Audi A4. The scanners that I have are limited to the OBDII generic fault codes for engine, ABS brakes and gearbox. They are fine for an engine misfire or similar but are of no help at all with any of the cars more advanced functionality such a alarms, climate control, steering wheel electronics or anything beyond the limited OBDII standard codes.I own VAG.COM for working on my Audi. It has saved me a lot on money as even a diagnostic scan costs around GBP40 at Audi. VAG.COM was specifically written for the VAG cars such as SEAT, VW, Skoda ad Audi. The key point I wish to make is that the manufacturer of VAG COM realised that generic diagnostics were too limited for the many faults that can occur on a modern car. He has worked on the software over the years, reverse engineering and collecting valuable OBDII VAG proprietary data (which has been hard to source). There are several microcontrollers in my A4 that talk over the CANBus and they can only be accessed with the correct proprietary VAG codes. Once you have that access you can do all manner of diagnostics, re calibrations (when replacing a part) and also reading of otherwise hidden fault logs. In some cases you have to 'marry' a new module to the A4's main computer.....only possible with Audi kit or VAG COM I think.VAG Com is a very polished product these days but it came from humble beginnings. I believe you will be best served by finding a commercial (Chinese) advanced OBDII scanner/programmer for your make of car, as this will hold the required interrogation and interpretation software that would be very hard to write without access to the manufacturers diagnostic kit. Without this essential manufacturer specific OBDII data you are unlikely to produce anything more useful than the US$30 OBDII scanners that I bought from China. If you have a simple engine fault, these scanners will do the business...anything else and they are very limited indeed .....even if they tell you the fault code, it will mean nothing if it is from the manufacturer specific error tables.Fraser

author: GeoffS
author_rank: Unknown
timestamp: December 21, 2012, 10:38:06 pm
content: I have a Scangauge II installed on my vehicle (Mercedes Van) and it works well in displaying the commons OBD parameters.It can be programmed to input specific codes to read a non standard value but that's as far as it goes. About $170I also have an ELM327 based device OBD <->- USB bought as a kit for $40 but you have to provide the software to drive it. There are several open source programs to do this but all are limited is what they can decode, the mandatory OBD stuff that is required in all vehicles but not the proprietary codes..I' have used a commercial software package and while it does support more decoding, it doesn't handle the proprietary stuff.To be able to decode all of the codes requires the Mercedes STAR diagnostic package but that is is over $20K.