Not your ordinary O2 sensor question.

[jps4jeep]

Both my hayes and chilton manuals give me the color and name of the 4 wires that are off of the O2 sensor, but I also need to know the values There is a high O2 sensor signal wire and a low sensor gound. I need to know the color, name, of all the wires!

cause I am wireing one of these up.

http://www.elmnet.net/~lange_c/837j.pdf

Thanks for any help!

 

[Tug-n-pull]

Oh yea I see how it is now! Your all about ask the really hard questions to see if you make the crew look silly right! Stump the jeepz peps. hehehe tug

Heck I bet someone will come up with this though.

 

[BostonJeep]

ill ask my buddy johnny, he'll know.

 

[XJNick]

Hi,

Your best bet is to look at a good electrical schematic for that model year (Haynes or Chilton don't count).

Though I doubt it will help you unless you own a TJ, the 02 sensor pinouts are as follows (for a '97 TJ and likely other years):

Upstream Oxygen sensor:
1) Heater +12 volts DarkGreen/BlacK
2) Heater Ground BlacK
3) Sensor Ground BRown/YeLlow
4) Sensor Signal TaN/WhiTe

Downstream Oxygen sensor:
1) Heater +12 volts DarkGreen/BlacK
2) Heater Ground BlacK
3) Sensor Ground BRown/YeLlow
4) Sensor Signal BlacK/DarkGreen

Also, you might be able to determine what they each do yourself, as Ground wires are usually solid black (in this case the solid black one is the heater ground). Then you could determine the 02 sensor ground by determining which of the remaining wires goes straight to ground. The 02 sensor signal wire will be the only one which runs straight to the computer, and the remaining wire will be the heater positive line. :mrgreen:

 

[Snitty]

do you NEED a heated sensor on there?

 

[jps4jeep]

Thanks Nick, But unfortunatly that is little to no help! The black wire is the 12 volts, and then I have a brown, gray, andwhite wire. also, yj's only have 1 O2 sensor. so there is no down stream up stream!, just one big fuggin river! hehe

Also, you can't use a multi-meter (according to autometer) to test the difference between the sensor signal and the sensor ground. I guess it is not like a chassi ground, cause that is done through the sensor itself to the threaded bung in the down pipe. IDUNNO! I think I am gonna wire it up and just guess. if it doesn't work and I fry te guage, I will just buy another, then I am out $50. and wire it to the other wire!


Snitty, apparently. Another option would be to buy a autometer O2 sensor designed for carborated cars, and weld my own bung into the downpipe and wire it off that, but all those parts would cost me more than if I have to just buy another guage if I screw this one up.

 

[Bounty__Hunter]

I've got the '95 FSM and here's the wires listed for the o2:
Black/Dark Green - Heated Oxygen Sensor Signal
Black - Ground
Black/Light Blue - Sensor ground at PCM
Dark Green/Orange - PCM

Should be the same as the '94. Don't look at the wires on the sensor as aftermarket sensors may have different colors. Use the wires before the o2 sensor connector.

 

[jps4jeep]

Thanks Bounty, I did look after the connector and they appeared to be the same color. I dunno, maybe I am dumb! or it was dark or i was drunk.

so many sinerio's so little time! hehe


Honestly thanks BH I will check it out when I get home!

 

[Bounty__Hunter]

Let me know, I can call a buddy with a '94 FSM and see if it's any different.

What's your plans with that guage? Just installing to keep an eye on things, or are you doing anything to modify the air/fuel ratio? I plan on installing an adjustible MAP sensor after my cam install so I can dial in the correct air/fuel ratio after all the mods.

 

[XJNick]

Hi,

Black should not be +12 volts. Yes, there are some wires which are black WITH a color tracer which might be hot wires, but I don't think I've ever seen a solid black wire used for +12 volts, it just isn't correct :mrgreen:

Be sure you are looking at the wire colors at the harness end, not the ones comming off the sensor (though, they should be the same).

As for the multimeter, you can use one to find the +12 volt heater wire, and the sensor and heater ground wires. The only wire left would be the signal to the computer. I believe the reason why this wire couldn't be tested easily is because it is at ground potential. That is, that signal wire is grounded through the 02 sensor which appears to act as a potentiometer (or variable resistor). That means that the resistance to ground on that signal wire changes depending on what the 02 sensor is detecting. The computer reads this resistance and uses it to determine the amount of oxygen present.

-Nick :!:

 

[White]

I have a a/f gauge but no help to you. I only have 1 wire sensor.

Sorry, Maybe its just easier to get a weld in fitting ? :lol:

 

[jps4jeep]

I got it wired up yesturday! works fine. I had the guage laying around thats the initial reason for installing it, but as I furture tear into the engine, I do want to keep an eye on the A/F ratio!

Bounty's wiring was almost 100% right, all except black/light blue, so I had to do a little guessing, so I figured since he said the blk/grn is the signal and I had one, why the hell not! oh well...

and Nick, Mercedes Benz in notorious for using black coded wires for 12 volt switch wires! they also use fiber-optics and vacumns to control door locks and window functions! wierd!

 

[White]

I was going to turbo the v6, Also have the Boost and Vac Gauge. The A/f seems to only be correct when using the gas, it just floats around at idel.