Freescale MC33290 Replacement
 

This info was hard to find, so I decided to make a thread. The SI9243 seems to be a replacement for the Freescale IC described in the OBDuino documentation and is available in small quantities at Newark (not Mouser or Digikey):

The relevant posts in the OBDuino thread are on page 69 (I can't post links).

the Si9241A seems to be a suitable replacement as well...
 

Someone else commented in the OBDuino wiki that the Vishay Si9241A works as well (tried and tested). I have ordered the Si9241A and am waiting for it to arrive.

Will provide feedback again after trying it out for myself.

What about the Freescale MC33660, available from Freescale as samples for $6 for 5......

Ordered 5 samples, received yesterday, excellent service........

I used SI9243 (only K line) and it works. Better quality schematic:
http://i40.tinypic.com/15hxt0l.jpg

Realization:
http://i41.tinypic.com/v8qa2p.jpg
http://i39.tinypic.com/xmikaq.jpg

OLD link: http://ecomodder.com/forum/showthrea...tml#post232163

Here you take +12V on car cigar socket? You take only +12V without car sigar socket's ground?

There is no need for additional +12V supply from car cigaret socket. The schematic gets +12V from OBD socket.
This schematic was used instead of MC33290 in standard OBDuino ISO diagram.
Link: OBDuinoDiagram - opengauge - Whole diagram of the Arduino board, LCD, interface - Open Source Fuel Efficiency Instrumentation - Google Project Hosting
P.S. Only difference is in 510R, which was increased to 560R (That I found in internet).
P.P.S. 1N4004, 100R was used for protection SI9243 (from SI9253 datasheet).

Best regards

I'm trying to make it with 9243. And for example pin1 of DB9 connects to 9243 and also somewhere else. On the other side that DB9's pin1 goes to OBD pin5. In my car, OBD pin5 doesn't have contacts. My car is a Rover. Any ideas?

1. I had very similar situation: In my car (VW Passat) in the cars OBD connector wasn't pin 4, which goes to DB9 pin 1 (GND ground). So I connected together DB9 pins 1 and 2 (OBD 4 and 5).
Have You looked in OBDuino page?
Link: OBDuinoInterface - opengauge - OBDuino OBD2 cable and Interfaces - Open Source Fuel Efficiency Instrumentation - Google Project Hosting
Link: OBDuino32K - opengauge - Homepage of the OBDuino32K Project - Open Source Fuel Efficiency Instrumentation - Google Project Hosting
2. Which OBD protocol is used in yours car (Rover) it is necessary to check in internet?
From OBDuino page link: OBD-2 Liste (erfolgreich) gescannter Fahrzeuge - Rover (2000 year) - ISO 9141-2

Best regards

Yeah I've looked at these pages.
My rover is older, 1997, as far as I know it uses the older iso 9141 standard.
How did you know which pins to connect together? I don't even know the correct orientation of my car's obd connector. But I checked either ways and in none of these pin 5 would have contacts.

I have suspicious, that your car doesn't have OBD-II standart support.
Does OBD socket looks like OBD-II?
Link: FAQ - opengauge - Frequently Asked Questions regarding the OBDuino Project - Open Source Fuel Efficiency Instrumentation - Google Project Hosting
Link: OnBoardDiagnostics.com - OBD-II Network Standards
I just asking, because OBDuino32k support only OBD-II standart (ISO (9141-2) and ISO14230-4 (KWP2000); CAN - only with ELM327 chip).
Earlier in the cars was OBD-I standard and everyone producer used his own OBD-I implementation. For example, VW has 2 sockets with 4 wires.
If so, it's necessary to use MPGuino,
link: MPGuino - EcoModder

Best regards

My connector wired holes do not look like any of these standards you posted, neither 9141-2.
As far as I know it uses iso 9141 standard.
So none obduino is for older 9141 and therefore I have to try to implement mpguino?

Sorry to say, but I'm not sure.
What kind of diagnostics equipment is used with Yours car?

I don't know about diagnostic equipment.
about mpguino... doesn't it connect to injectors instead of to OBD?

1. Maybe it will be useful:
Link: 200/400/600 Fault Codes
2. mpguino is connected directly to engine; it don't communicate with cars computer.

I am looking to build my own OBDuino. However, I am running into parts availability issues. I am looking for a replacement for the Si9241A / SI9243 chip. The originally used MC33290 is long since obsolete, and it seems the Si9241A and SI9243 are now also obsolete. Does anyone know of another valid replacement?