Thread: Regrounding the O2 Sensor

I've got a new (>3K miles) 3 wire (bosch 13039) installed on my car right now. I've also got the older o2 sensor that has the black white red wiring that DC Scotty and 228k_ser had which I used as a donor for the sensor socket clip, it has a black, white and red wire.



I wired up a 4 wire bosch 15727 according to this and was about to install it when I decided to do another check just to see, and I came across a potential problem.

The wires on my bosch 13039, plug into the o2 sensor clip W-B-W with black being the signal wire I'd guess, from this I assume the middle connector is for the signal. So I look at my 15727/older connection and I've got B-W-R going into the sensor clip. So on this one if Black is the signal it's in the left side not the middle. ???!

To me it looks like I've got the sensor crosswired. but to make it work I think I'd have to hook the 15727 black wire to the older o2 white wire (the middle one, and hook up a white and black the other way as well.) This makes no sense to me.

can some of you check to see what socket your signal wire plugs into and let me know.

Thanks for the help.

BE VERY CAREFUL! Crossing the wires over can fry your Sensor and ECU!

The Bosch # 15727 is as follows:
Black = Signal
Gray = Ground
White = Heater/ Heater Ground
White = Heater/ Heater Ground

The heater wires do not have polarity, so thats why there are two whites.

I hope that helps

I can see your confusion.. Let me simplify this!

1. Look at your O2 Sensor Harness wiring on your main harness (do not wire based on the donor plug wire colors).
2. Determine the signal wire and heater wire plug locations.
3. Wire the Universal O2 sensor to a donor plug based on the results of #2 above.
4. Create the grounding wire harness with a O-ring for the Intake Mani end and a bullet connector at the O2 plug end.
5. Plug in the Universal O2 sensor donor plug. Plug in the O2 grounding plug.

In your case, Your O2 harness is probably W-B-W.
So wire the 15727 O2 sensor to match it.
Hopefully this help simplify this for you.

My 15727 O2 sensor is wired W-B-W.





Note: I used a larger gauge wire for the grounding wire (to account for the distance to the Intake Mani)...

Thanks thought I was going a bit crazy last night, but I'm glad I checked before installing the o2 sensor. My current sensor (bosch 3 wire oem) looks just like DCScotty's

I'm guessing that the black wire is the signal. and the 15727 instructions confirm that. It attaches to the middle prong of the coupler.

This is what my old coupler looks like

I wired it up black signal, red and white heater wires, (per this thead) but as you see that puts the signal wire on the side not the middle.

So just to make sure I've got this right I'm going to wire the black (signal) 15727 wire to the middle (white) wire of the coupler, and the two white heater wires to the Black and Red wires of the coupler. That's got all the wires mismatched but connected to the right prongs of the coupler.

Hey Guys.. Wilser is CORRECT!!!
I went back to validate the Engine Harness wire at lunch today.

The information that I posted earlier was from the Bosch Online O2 wiring description for Replacement O2 sensors. The information is appears to be incorrect for the Nissan OEM O2 sensors with Red, White, & Black wires.

The correct 3-pin plug wiring is as you described:
Middle wire is the signal wire
Outside wires are the heater wires.

Our rainbow OEM wire colors are simply screwy and does NOT match the industry standard. I have corrected my original post!

Great Catch Wilser!!
We dont want to cause any damage with incorrect wiring..

Great, can you break that down into colors?

Left Wire
Middle Wire
Right Wire

Nope, not yet...

May not be consistent across all cars.. or same model either..

Im doing more investigating tonight..

UPDATE

After looking in the Sentra, G20, & NX FSMs, Im finding as I first thought, we have a rainbow of different color Nissan harness wiring.. Shame on Nissan!! The NX's alone has 6 different variations between year & tranny type..

We can only do this by position. The middle pin is always the Signal wire from what I can find. And the 2 outside wires are heater pins. I will continue to read wiring diagrams to validate this statement. But sofar, this is true statement for 3-wire sensors on Sentra's & NX's. I will checkout the G20 wiring later tonight.

for the 15727 the middle wire is black the outside two are white. Grey is ground.

On the bosch 3 wire oem replacement, the signal wire is black and the outside wires are white.

On the nissan oem 2 sensor for a highport 93 MT b13 sentra se-r the signal wire is white and the heater wires are red and black.

as DC says there appear to be many variations of ranbow flavors of nissan oem o2 sensors so go by tab position rather than color.

Middle plug is signal, outside plugs are heater wires.

Middle pin should be signal not ground right. outside two are heater.

Good catch, Scotty called me and I think I said ground one too many times so he got it mixed up