I *ahem* accidentally removed my air temp sensor from my new wiring harness, and am reinstalling it, but am not sure which plug at the ECM the wire labled BR/B goes in?

I cant read this schematic too well, but it looks like several sensors are on the same wire, is it a ground?

I detailed what wires in my 2nd grade coloring project:

 

Yes, BR/B looks to be the sensor ground. You should be able to tap into any other BR/B wire that is also connected to a sensor. The BR/B line connects to the other ECU plug (the one on the right of the diagram), at the pin labeled 4F.

-s-

 

I concur

 

It is not a ground. It is a regulated 5v source for most of the sensors and does not come from the ecu. The closest connector is by the fuse/relay box by the battery.

 

Gadd, according to the Mazda wiring manual, that's ground.


Page Z-32 shows the BR/B line connecting to the PCM at terminal 4D.
Page Z-38 labels terminal 4D as ground (input).


-s-

 

TPS and MAP are the only sensors that need a 5V reference.

 

opps it does go to the 4D at the ecu But it is NOT a Ground.... The 5V is used by the tps, map, air intake, water, fuel temp, ect sensor......

 

So there is no problem with me splicing into 4D at the ecu connector then? 'Cause thats my plan.

 

Yes, you should be OK, but I'd personally splice into a sensor wire in your engine bay, if that will allow you to run a shorter wire.

-s-

 

So, uh, I spliced the green to the G, and the brown/black one to BR/B, reconnected battery, and now the PFC wont power up, at all. I pulled the BR/B out of the plug, and spliced it instead into the BR/B on the TPS plug (the BR/B has ~4 wires in it, then it goes to a blue plug and a yellow plug at ECM), hoping that it would help...no dice. Did I fry the PFC?

 

that's what you were should have done from the beginning. When you spliced it into the ECU plug, you included the harness side into the splice as well, right???

check you fuses, and make sure you have everything connected.

I can't find what 4D actually goes too...I traced BR/B all over the place and it terminates to the shielded wire on the ignitor/coils cable via X-05 which then turns to B/LG. But I never saw it go to the ECU.

I have no idea what you are talking about...4D Br/B is an INPUT GND into the ECU.

 

Which fuses deal specifically withe the ECU, if any? Because all of the other electronics in the car work still. All of them.

 

the first to blow would be 10A ROOM...which also illuminates the key hole, audio, power antenna, and theft. Did you check all of those?

 

Radio works fine, antenna goes up/down fine.

 

Maybe you blow your pfc

 

Can you start the car with pfc installed?
If yes then you propably have burn a part o pfc if your car didnt start with pfc and start with mazda original ecu then you have burn the pfc.

 

I didnt try to start the car after I noticed that the PFC commander wasnt powered up. I figured there was a problem at that point, and decided not to risk any further damage.

As for using the stock ECU, I eliminated all of the turbo control/emissions etc... so if it did start, it wouldnt run correctly.

Is there a way to driectly test the PFC to see if its fried or not? I cant read japanese, and the www.apexi-usa.com manual is decidedly brief. Thanks!