My car has 2 different plugs. One, under the bonnet, is a diagnostic connector which operates as you describe. In this case I short 2 pins. GND and TEN (test enable), the car will then flash any error codes on a LED connected between two other pins(can't remember which at the moment) The other plus is an OBDII connector, inside the car in the fuse box. This is where the factory diagnostic system connects. Through this plug you can access a whole lot more information including throttle position, load, intake air temperature, exhaust gas temperature, RPM, speed, individual wheel speeds if ABS is fitted, oxygen sensor voltages, short term and long term fuel mixtures and a bunch of other stuff, it will also tell you if any sensors are malfunctioning, whether any sensors have abnormal readings and any error codes like the diagnostic plug. -----Original Message----- From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU] On Behalf Of Jason S Sent: Tuesday, 8 June 2004 11:28 AM To: PICLIST@MITVMA.MIT.EDU Subject: Re: [PIC:] Project suggestions... Something I'd like to build is a reader for the car's on-board computer diagnostic error codes. The service manual just doesn't have enough information to build it. There's a plug that's supposed to connect to the repair shop's diagnostic machine, but the service manual does give instructions to short 2 pins together on that plug to make it flash out the codes on the lights on the dash. Then you look the numerical code up in the service manual. I'd like to build a device that plugs in, reads the code electronically, and displays it on an LCD along with the text explaination. Jason ----- Original Message ----- From: "Nikhil Praveen" To: Sent: Monday, June 07, 2004 6:03 PM Subject: Re: [PIC:] Project suggestions... How about a PIC based electronic ignition for cars that have conventional points system ignition? ___________________________________ Telecom disclaimer can be found at: Http://www.telecomfiji.com.fj/disclaimer.htm ------------------------------------------------------------------------- This e-mail message has been scanned and cleared by Trend Micro InterScan ------------------------------------------------------------------------- -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.