Can you help me identify which wire is what?


This is the sensor side of an O2 sensor from a OBD-2 car. What wire is what?

(*Edited with answers)
Black #1 = Heater Ground (-)
Black #2 = Heater Power (+)
White = Sensor Signal (+)
Green = Sensor Ground (-)

Im hooking up a wideband and I want to solder this connector up and use my existing O2 wire harness. I need signal, switch 12v power, and ground.


Modified by Muckman at 4:04 PM 1/14/2004

 

White: O2 Sensor Signal
Green: O2 Sensor Ground

If you plug the sensor back into the harness the 2 black wires will go to a yel/blk and org/blk. yel/blk is 12v switched source and the org/blk is 12v 02 Heater.

 

Maybe the wires turn into something different when I plug my AEM EMS in bc I called AEM and asked for help on this matter and they told me white is power, green is signal, black is ground and the other black wont get used. Thanks for the help.


Modified by Muckman at 2:38 PM 12/10/2003

 

The AEM EMS is a plug-n-play system, right? Assuming so, it should control the heater and read the O2 output on the same wires that are used by the stock ECU....so they shouldn't turn into anything different.

*That O2 connector looks mighty familiar.... *


Modified by EE_Chris at 3:04 PM 12/10/2003

 

Chris your absolutely right, as always. But for some reason it doesnt use both grounds. Im not sure if the sensor and the heater can both use the same ground but I dont see why not.

Thanks for the connector, its a life saver!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">... Im not sure if the sensor and the heater can both use the same ground but I dont see why not.</TD></TR></TABLE>The sensor ground has to be there all the time. The heater ground goes to the ECU. The ECU closes that wire to ground whenever it wants to turn on the heater.

 

Do you know for a fact the O2 heater is not on all the time with a stock ECU?

The AEM EMS has this wire (heater ground) always closed, meaning its always grounded, meaning the heater is always on when the ignition switch is on. This pin is a configureable output and is set to be enabled under all vehicle conditions all the time. This is the way its setup on all the basemaps for Integra/Civics using the AEM EMS.

I had an extensive talk with AEM EMS techs about this and they said this doesnt cause any problems with the stock O2 being on all the time. And hooking up the AEM Wideband controller's ground wire to this wire will work sufficiently too.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">Do you know for a fact the O2 heater is not on all the time with a stock ECU? </TD></TR></TABLE>Actually, no I don't. I just figured if they wanted it on all the time, why bother running the wire to the ECU? They could just ground it right there & let the main relay turn it on. One less wire, one less pin at the ECU, one less output transistor in the ECU, ????

 

Very true. I just know that AEM just leaves it on 100% of the time and it doesnt cause any problems. It will make my wiring alot less messy if I can wire my wideband directly and completely into the existing wire harness and even use the connector in case I need to swap it out.

Thanks for your help Jim, and of course Chris