View Full Version : Make your own diagnostics tool :D

24th February 2010, 09:25 AM
All you electronics nerds out there... :l33t:

Boss just handed me this months Silicon Chip magazine... make your own OBD tool.. can even buy the kit complete and put it together yourself :)

OBDII Interpreter: Main Features

• Enables checking for diagnostic trouble codes
• Clears trouble codes and Malfuntioning Indicator Lamp (MIL)
• Shows real-time data
• Extra features are software dependent
• Interpreter interfaces between the vehicle’s OBDII port and a computer
• Serial or USB connection (via an adaptor) to computer
• Power for the OBDII Interpreter obtained via the vehicle’s OBDII port
• Works with CAN, ISO, KPW, PWM and VPW protocols


24th February 2010, 09:59 AM
How much is the kit?

24th February 2010, 10:01 AM
do they do one for an OBD I ?

24th February 2010, 12:15 PM
Remember that most opels are not fully iso compliant (hence the popularity of opcom)

My elm based one (im sure the SC project will be based on an elm interface or similiar) has limited functionality on the astras/veccy, although works well on most jap cars (except the mrs suzuki dammit!)

Good project, although i wonder how many non technical ppl will fry their ecu's trying to get it working :D

24th February 2010, 12:34 PM
im gunna make one anyway and see how i go... chip is ELM327 btw ;) (not the chinese knockoff ones the keep spitting up errors etc)

the magazine has the info on making an OBDI one aswell but couldnt find it on the net, not sure how much the kit is worth but ill let u all know

24th February 2010, 12:45 PM
the elm327 chip is pretty nice

especially nice is that the communication protocol to the chip is well documented on the manufacturers website. you just need to send/receive ASCII strings to it and it'll tell you anything you need. easy stuff, i wrote a custom app to record acceleration runs and make graphs of sensor values

the only thing i dislike about it is the time needed between requests to the ECU. with my Barina you won't get responses to requests at more than 5Hz - each request only gives you the value of a single sensor at a time as well!

24th February 2010, 12:48 PM
btw how much is the kit? because you know you can buy premade ones with a genuine ELM327 for about $100 right :)

24th February 2010, 08:01 PM
The Silicon Chip "design" is nothing to get excited about .. and I use the word design very loosely.

They have taken the reference design from the ELM327 data sheet, added a MAX232 driver for the serial port, designed a fairly crude PCB layout, and re-drew the schematic to look a little nicer. Even the component designators have been copied from the data sheet.

24th February 2010, 10:16 PM
I thought this thread was about how to unbend a paperclip :p