NytWolf

So I'm finished with my swap, somewhat, but there is a Check Engine Light.

When I hook up a CAN OBDII machine to it, it doesn't read it. Says "no communication". I also try a Snap-On OBDII scanner, same thing. Says "no communication". I have read that some scanners can't read all vehicles. I'm hoping that's the case, that these two machines just can't read my ECM. But I just want to be sure (for the CA smog test).

So, on a 2000 Tacoma, what pinouts are supposed to be used on the OBDII connector? It's only four wires, right? I have an ORS harness, and haven't touched those wires.

I looked through my TIS downloads and can't find the reference to it.

Quick Draw

On my wiring diagram for the ECU, the OBD2 connector is in a little box called "data link" or "data connection link" or something along those lines... I don't have it in front of me, otherwise I could tell you exactly. On my 1996, it was 4 wires. But I have heard that later years had more pins, and switched around wires, etc. So I would check into that. Also, 2 of the 4 wires on mine were grounds...which makes very little sense to my simple mind... If there is a ground terminal on the harness somewhere that isn't hooked up, that would do it too.

NytWolf

You mean on the ORS harness? I have only one ground on that harness, and it is grounded.

I found the "data link" on the diagrams and those look to be by the books. There isn't a section for just the OBDII connector to ECU diagram, right?

NytWolf

So on my diagram, the "Data Link Connector 3" on my 2000 Taco uses pins 4, 5, 7, and 16. But the OBDII ISO 9141-2/KWP2000 says pins 4, 5, 7, 15, and 16 must have metal contacts. According to mine, it is missing a 15. Is that okay?

Pin 4 is chassis ground
Pin 5 is signal ground
Pin 7 is the ISO 9141-2 K Line
Pin 15 is the ISO 9141-2 L Line
Pin 16 is the Battery Power

Does anyone know if both pins 7 and 15 MUST be used for the reader?
EDIT: Okay, I found that pin 15 (L Line) is optional, from the ISO 9141-2 standards. So ... now ... I ... must ... go ... check ... ing ... lines ... a ... gain. That sux.

hamish_18

you want the obd2 connector on the harness side to match up with what the ewd says.

NytWolf

Yeah, the unfortunate part is that mine does match up, but the scanners still don't read it. Not sure what else to do. Is there anything I need to do besides just plugging in the scanner?

hamish_18

you have the right scanner? it has to be the ISO standard. I know mine is the GM or ford version, but I have a 97.

NytWolf

I'm not sure. One of them is a CAN-OBDII reader, didn't catch the brand. The other one is a Snap-On OBDII reader. It's pretty neat, and you can see it switching the protocols trying to make a connection.

upsidedown

iTrader: (1)

do you have the key on? right before the truck starts. make sure the pin locations are right for the year ECU you are using, how is the battery?

NytWolf

I fixed it yesterday. My switched +12V to the E5 connector of the ECU wasn't working. Once I provided power, it is working now.