Can I re-pin this plug?

[thebigtuna]

Hey Everyone!

I am in the process of replacing my shifter cable as one broke on me. I noticed these three wires open in the bay and found the plug I believe they go into it. The plug leads to the Air/Fuel Ratio sensor in the downpipe. Does anyone have a diagram or tips on how to re-seat these pins in their proper location? I've tried searching online for diagrams and threads but haven't come up with much. Any help is appreciated!

2007 Stock MS3

 

[Awafrican]

Should be able to re pin it. Usually once the pins are taken out they should just slip back into place and lock in to get them out you need a.pin tool. Now unless they've fallen out because the retainer on the pin or in the plug has broken then you're looking at replacing the item affected.

Checkout this thread it may be of help

https://mazdaspeeds.org/index.php?threads/harness-plug-and-other-useful-connectors.7659/

we have the wiring diagrams and shop manuals hosted here for metal members (accessed via the donate / account upgrades tab)

 

[thebigtuna]

I guess I'm just a bit lost still. I donated and am looking at the wiring diagram but I'm a bit of a dummy when it comes to this stuff. I believe I'm looking for the front heated oxygen sensor (The one right next to the turbo) for the 2.3L engine which is page 37 of the doc you posted. But, I don't see any of those colors in my engine bay. I don't quite understand how to read this to figure out which pins are supposed to line up. I think I'm looking for the 3 NCA's, because they run through the little plug on the diagram? Does this sound right?

 

[Awafrican]

If you open the 2010 MS3 wiring diagram head to Pg 72 (PDF Pg 74) the pinout for the HO2S and A/F Sensor are there VS the PCM pin you can check for continuity back to the PCM and confirm which is supposed to be which that way which honestly is probably how I would do it to be sure if you can't make out stripes on the wires

If you look at your original pic you can see the second connector which would be for the A/F sensor the green, red ?black and W/? go to it.

This should leave the LG, BR, SB and Y to the HO2S.

I'm not the best at wiring perhaps @JohnnyTightlips can provide some insight

 

[thebigtuna]

Is that the same for a 2007? I only have 3 pins going to the HO2S. I'll work on the continuity and see where this pins end up on the pcm. Thanks for the help so far!

These are the two plugs that both seem to run to the HO2S. White, Light Grey, Black, Blue, Yellow. I can't see

 

[Awafrican]

Yeah should be the same? 4th one could very much be a blank. I'm hoping JT pokes his head in here.

 

[thebigtuna]

I found continuity from all three pins and they seem to be 1A, 1B, 1C on the HO2S plug you linked. Wire colors from the PCM seem to line up with the wiring diagram so I'm feeling rather confident. Got them put back in the plug and taped it up so hopefully its correct and holds. Guess I won't know till I give it a test drive. Need to do a once over before testing tomorrow after work. Does the stock ECU use the oxygen sensor for anything, will it throw a check engine if it's not correct? I installed an AFR gauge on my turbo miata but I only used it to adjust fuel, the ecu didn't care what it saw really, only I did.

Fingers crossed it works and I did it right. Thanks for all of the advice! Always something. Go to fix one thing and find one or two more problems I can't ignore while I'm in there LOL.

 

[Awafrican]

Sounds like you got it sorted, glad to hear

oh yeah that upstream O2 sensor is for AFR car will pull or add fuel accordingly...the H02S heats up the sensor so that the o2 sensor operates at a specific temp, idle doesn't even get the sensor hot enough to function properly. You'd get some Codes yup checkout Pg: 01-02A-17 in the 2010 mazdaspeed 3 shop manual mil on, generator warning light off, for things like p0031 or p0054, could toss some other o2 sensor codes too I'm sure if its not warm enough to function properly etc.

let us know how it goes