|
High Speed ISO9141 Interface |
|
Monday, 09 July 2007 |
This project is a high speed ISO9141 interface based on not opto-isolators but a dedicated ISO driver IC, the Motorola MC33290D.
| | 
| This project is a high speed ISO9141 interface based on not opto-isolators but a dedicated ISO driver IC, the Motorola MC33290D. Using a dedicated IC gives many advantages: - High speed operation, upto 115.2kpbs as required by VAG-COM 404
- Electronics protection against bus short circuit.
- Wide operating voltage
Pin 6 and 5 can inteface directly to a microprocessor but to connect to a PC's serial port a voltage level converter as such a MAX232 must be used. | | | | | | | | | | | | | | | Full schematic in pdf can be download here. The schematic is release under GPL license. Anyone can use it for non commercial purpose. As this is a free project I do not provide support on this. Please read the FAQ below. | | | | | | | | | | | | | | | | | | Parts List | | | | | | | | | | | | Designator | Value | Description | |
|---|
| R1 | 510R 1/4 W | 510R 1/4 W resistor | | | C1,2,3,4,5,6 | 0.1uF 16v | 0.1uF 16v capacitor | | | C7 | 10uF 50v | 10uF 50v capacitor | | | U1 | MAX232ACSE | MAX232ACSE level converter IC | | | U2 | MC33290D | MC33290D ISO driver IC | | | U3 | LM78L05 | LM78L05 Voltage regulator | | | | OBDII Connector | OBDII Connector | | | | | PCB | | | | | Ready made module | |
| | | | | | FAQ Q: Where is the L-Line?
A: Older ECU uses the L-line to "wake-up" but now days modern ECU uses the K-line for this. Q: Does it work with VAG-COM Release 409.1?
A: Yes. Q: Does it work with VAG-COM Release 512.1?
A: No, this version requires an interface with build in dongle. The Key series will work with 512.1 Q: Does it have dual K-Line?
A: On 2002+ Audi A4, A6 some modules are on the second K-line (formerly L-Line). If you want to connect to the L-Line add a single pole change over switch. | | | | | | | | | | | | | | | | | Useful Links Ross-Tech - Excellent software compatible with this interface. Free shareware version available for download. Opendiag - Yahoo Group discussion of open approach to interfacing with automobile. | | | | | | | | | | | | | | | | Disclaimer Use the schematic at your own risk. Improper use may damage your ecu. In no event will skpang be liable for any damage whatsover (including without limitation damages relating to lost revenues or profits, lost data, work stoppage, computer failure or malfunction) resulting from or in any way related to the use of the OBDII Interface. | | | | | |   |
|
