psedog Posted April 28, 2020 Report Share Posted April 28, 2020 Hello all, Installed a week or so ago. I'm trying to get a few things setup/configured. IAT. I want to use the MAF line. I used the 1K resistor between 12V and the sensor, but the voltage only pulled down to 7VDC. Obviously not low enough I messed with the wiring and ended up blowing my IAT sensor. Stupid me, lol. I knew it was going to happen when I put it parallel to the 12V/GND. Anyway, while I have one on the way I decided to go a different route. It needs to be 5VDC, correct? I have DC/DC buck converters. I set one up as 5VDC and tested it with a 9V and 12V power supplies and it stayed at 5VDC for both. So, I know I have a stable 5V to work with. Do I just wire that into the IAT and put the sense wire onto the hot side? I feel like that wouldn't be right and would still blow the IAT sensor. Update: IAT is good. New Cal values added to the table. Thank you @Adamw for making sure I didn't make another bonehead mistake. SSM/ODB2. The SSM connector is still getting a 5VDC signal across the wire coming from the Link ECU on pin 31, which the Link documentation doesn't show anything. This could be TTL or just plain old 5V, I don't know. I'd like to know if there is a way to reconfigure the connections that aren't being used. I want to hook up a ODB2 connector under the dash and it would be awesome if I could use existing wiring. I was able to de-pin the USB wire and slid it through one of the bolt holes in the case. I'm planning on doing the same with the CAN connection for the wideband O2 sensor when it gets here. Quote Link to comment Share on other sites More sharing options...
Brad Burnett Posted April 28, 2020 Report Share Posted April 28, 2020 Iat sensor is just signal and sensor ground. with the link ecu the obd2 port will only work if you hook CAN high and low up to the appropriate pins. But not like a standard obd2 port. It will not give you codes or readiness functions. just data from the ecu such as temperatures/rpm/speed/etc. Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 28, 2020 Report Share Posted April 28, 2020 You need a 1K pull-up between the AN Volt wire and 5V. 10 hours ago, psedog said: SSM/ODB2. The SSM connector is still getting a 5VDC signal across the wire coming from the Link ECU on pin 33, which the Link documentation doesn't show anything. This could be TTL or just plain old 5V, I don't know. I'd like to know if there is a way to reconfigure the connections that aren't being used. I want to hook up a ODB2 connector under the dash and it would be awesome if I could use existing wiring. Pin 33 is not connected to anything in our ecu, it is just a blank pin, so the 5V is not from the ecu. Are you sure it is pin 33? Our diagrams show pin 33 was originally from the idle switch. Pin 31 & 32 are marked "Diag" in our schemaitic so I would say that is more likely. Quote Link to comment Share on other sites More sharing options...
psedog Posted April 29, 2020 Author Report Share Posted April 29, 2020 8 hours ago, Adamw said: You need a 1K pull-up between the AN Volt wire and 5V. Pin 33 is not connected to anything in our ecu, it is just a blank pin, so the 5V is not from the ecu. Are you sure it is pin 33? Our diagrams show pin 33 was originally from the idle switch. Pin 31 & 32 are marked "Diag" in our schemaitic so I would say that is more likely. It's on the 5V, no wonder it didn't work with the 12v from the maf wiring, . I looked at that too. Must have glossed over it. New sensor got here today, so I'll wire that up today. It makes sense that a resistor was still required. I was going to use a 1ohm just to limit current if you hadn't chimed in. Thank very much. You are correct, it is pin 31. Trying to bounce back between the two different wiring tables can be confusing, lol. B96- 7 and 8 are pins 31 and 32. Quote Link to comment Share on other sites More sharing options...
psedog Posted April 29, 2020 Author Report Share Posted April 29, 2020 19 hours ago, Brad Burnett said: with the link ecu the obd2 port will only work if you hook CAN high and low up to the appropriate pins. But not like a standard obd2 port. It will not give you codes or readiness functions. just data from the ecu such as temperatures/rpm/speed/etc. I'm aware. I'm going to hook it up to a OBDII to Bluetooth adapter and use RealDash on my phone. It would be real nice if I could take advantage of the stock wiring though. Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 29, 2020 Report Share Posted April 29, 2020 8 hours ago, psedog said: It would be real nice if I could take advantage of the stock wiring though. We cant unfortunately, it is illegal in most countries to have any device connected that is capable of manipulating the legislated OBD2 functions. Quote Link to comment Share on other sites More sharing options...
psedog Posted April 30, 2020 Author Report Share Posted April 30, 2020 2 hours ago, Adamw said: We cant unfortunately, it is illegal in most countries to have any device connected that is capable of manipulating the legislated OBD2 functions. It's a 95 wrx in Japan. No OBD stock. I was just hoping to use the wires for something other than just dead weight. Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 30, 2020 Report Share Posted April 30, 2020 CAN wiring is meant to be twisted pair, if they are short you may get away without them being twisted pair. Quote Link to comment Share on other sites More sharing options...
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