O2 sensor wiring help (1 Viewer)

[snatchfj80]

guys, need help i found that my outside cat o2 sensor is not hooked up anymore and that is why i'm getting a code 21 wheni read the codes, but the PO must have replaced broke off the plugs but neither the harness or the o2 sensor have plugs, and there was a weird connector device, the problem is there are four colored wires coming from the harness (yellow, blue, grey and black) and the o2 sensor has (2 white, black and a gray) so i don't have a wiring diagram yet and don't know which wires go to which, because i'm sure it matters. thanks for taking a look

 

[silverhorse]

bump Can somebody help a brother out?

 

[superjuice]

Not sure what the colors are coming from the truck, i dont want to cut open the loom. This is what my O2 sensor connector looks like ...HTH

 

[snatchfj80]

thanks for the pics of your o2 sensor, does anyone have pics of the harness side plug for the o2 sensor?

 

[MoJ]

Try post 16 in this thread to help match up the wires.
https://forum.ih8mud.com/80-series-tech/295795-code-26-a.html


I can't tell from your pic.....are those aftermarket resistors on the end of each wire?

 

[Marc311]

Try post 16 in this thread to help match up the wires.
https://forum.ih8mud.com/80-series-tech/295795-code-26-a.html


I can't tell from your pic.....are those aftermarket resistors on the end of each wire?

Those are Posi-lock connectors. They're pretty cool and re-usable. Save them for later if you don't re-use them.

Posi-Lock(R) - The Best Connectors You'll Ever Use!

 

[akarilo]

Get a multi-meter out and check current on the wires. You're going to have (1) hot and (2) grounds, or vise-versa. The fourth wire is the voltage signal wire, (I think it's the blue one). The sensor output signal range is very low, under 1 volt if I recall. It should be a no brainer with a multi-meter.

Also look up some Bosche O2 sensor generic wiring diagrams.

 

[snatchfj80]

no those are some weird connectors the PO tried to use(didn't work well though

 

[snatchfj80]

thanks for the info akarilo, will let you know how it turns out, have to wait till i have another day off and no snow

 

[snatchfj80]

still looking for a pic of the o2 sensor harness on the truck side, this is the o2 sensor on the outside of the truck(closest to the passenger side door) pics of the wires going into the plug as well as the plug, thanks

 

[snatchfj80]

update, tested the 4 wires coming from the truck side harness(main o2 sensor) and have 1 hot wire(3.5-8.5) 2 wires with .1 and 1 with .1-.3 volts. If i have researched this correctly(please correct or help me if you can) the the 1 wire with 8.5 and one of the wires with .1 is the heater wires and the 1 wire with .1-.3 is the signal wire and the last wire would be te ground
truck harness side
yellow/red 3.5-8.5
black/yellow .1-.3
gray- .1
blue/white- .1
I also found a bad main o2 sensor with harness and plug from toyota inside of my truck
and aslo found the o2 sensor in the truck now is a bosch universal o2 sensor, so from looking at the fsm for the electrical system
i was able to figure out what harness wires go to what o2 sensor wires
truck plug
gray(1) yellow/red(2)
blue/white(3) Black/yellow(4)

sensor plug(just the wires don't have plug on universal o2 sensor)
White(2) white(1)
gray(4) black (3)

I also used the thread that MOJ placed in this thread
using what i learned there and from the universal o2 sensor instalation sheet from bosch it looks like i should have the right wires identified and ready to connect, just would like some input from some more knowledgeable forum members before i go ahead and potentially fry my ecu if i'm wrong, thanks for reading all of this and hopefully understanding it

 

[snatchfj80]

update, i ended up wiring the o2 sensor just like my last post and i cleared the engine light code before i restated and test drove the lc, it worked and the engine light has not come back on, thanks for all the info on this o2 sensor deal

 

[buggydude]

Not sure what the colors are coming from the truck, i dont want to cut open the loom. This is what my O2 sensor connector looks like ...HTH
View attachment 384171

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View attachment 384173
View attachment 384171View attachment 384172View attachment 384173

Thank guys old post, had wires ripped out of the plug