Need help identifying wires on a destroyed air fuel sensor connector

[ronin95]

This is a 2000 Cali SR5.

The air-fuel sensor connector (vehicle harness) was destroyed by the previous owner, leaving only dangling wires. I have a replacement connector shell but I can't seem to find accurate information on the wiring color codes anywhere online.

The 4 wires are:
2 larger gauge wires - brown and brown-unclear color, which I'm guessing are the heater.

2 smaller gauge wires - brown and black, which I assume is the AF signal, but I have no idea of the polarity.

Can someone with a '00 EWD please help?

 

[Drew76]

I just looked at my wiring diagram, I have a 2000 Cali emissions truck, assume you are indeed looking at the A/F sensor (upstream sensor), wires look to be different to what you are describing

#1 designation at A/F sensor is wire L (Light Blue) - goes to ECM as HTAF1 - looks like the heater
#2 designation at A/F sensor is wire W-L (white/light blue) splices in with lots of other wires from ECM (I11) - common or gnd maybe
#3 designation at A/F sensor is wire W (white) - goes to ECM as AF+ - signal positive
#4 designation at A/F sensor is wire B (black) - goes to ECM as AF- - signal negative

Downstream 02 sensor

#1 red/white - HTS
#2 white/light blue - I11 splice
#3 red - OXS
#4 brown - another I11 splice

I might be crawling around under my rig later and can have a look at my wiring

 

[ronin95]

I just looked at my wiring diagram, I have a 2000 Cali emissions truck, assume you are indeed looking at the A/F sensor (upstream sensor), wires look to be different to what you are describing

#1 designation at A/F sensor is wire L (Light Blue) - goes to ECM as HTAF1 - looks like the heater
#2 designation at A/F sensor is wire W-L (white/light blue) splices in with lots of other wires from ECM (I11) - common or gnd maybe
#3 designation at A/F sensor is wire W (white) - goes to ECM as AF+ - signal positive
#4 designation at A/F sensor is wire B (black) - goes to ECM as AF- - signal negative

Downstream 02 sensor

#1 red/white - HTS
#2 white/light blue - I11 splice
#3 red - OXS
#4 brown - another I11 splice

I might be crawling around under my rig later and can have a look at my wiring

If you can verify it visually that would be amazing! It is indeed the upstream A/F sensor. I have no idea why my wiring colors are so different from any documentation I've found. I've pulled it out of the plastic loom as far as I can and it definitely wasn't spliced.

 

[gamefreakgc]

Do you have a local pick n pull yard near you? Honestly I'd just poke around and look at the hood sticker until you find a 99+ with California emisisons and then snip the connector. Could pull the sensor too.

 

[ronin95]

Do you have a local pick n pull yard near you? Honestly I'd just poke around and look at the hood sticker until you find a 99+ with California emissions and then snip the connector. Could pull the sensor too.

Getting a snipped connector won't help if I don't know how my vehicles wires to it. Also, I have a new connector shell, the wire pins are still fine. I just don't know what wire goes where on the connector.

Even more confusing is that I got someone to take a pic of their 2000 California AF wires and their colors are completely different than mine. I'm baffled.. how do I even proceed? My vehicle contradicts both wiring diagrams and another similar vehicle.

 

[TheDurk]

Getting a snipped connector won't help if I don't know how my vehicles wires to it. Also, I have a new connector shell, the wire pins are still fine. I just don't know what wire goes where on the connector.

Even more confusing is that I got someone to take a pic of their 2000 California AF wires and their colors are completely different than mine. I'm baffled.. how do I even proceed? My vehicle contradicts both wiring diagrams and another similar vehicle.

Well, if you have the EWD, you know where the wires connect to. I believe three connect on the ECU, and one connects directly to 12V+ from the EFI Relay. So pull your battery negative, and rig a long lead to your DMM on resistance. Connect AF+, AF-, and HT- in turn on the ECU terminals behind the glove-box, and see which wire in the harness has continuity. Replace battery terminal, switch DMM to DCV and verify the fourth wire has 12V+ with EFI relay on, and open when it's off. Voilá!

It will also be interesting to see what colors those wires are when they hit the ECU.

 

[ronin95]

Well, if you have the EWD, you know where the wires connect to. I believe three connect on the ECU, and one connects directly to 12V+ from the EFI Relay. So pull your battery negative, and rig a long lead to your DMM on resistance. Connect AF+, AF-, and HT- in turn on the ECU terminals behind the glove-box, and see which wire in the harness has continuity. Replace battery terminal, switch DMM to DCV and verify the fourth wire has 12V+ with EFI relay on, and open when it's off. Voilá!

It will also be interesting to see what colors those wires are when they hit the ECU.

Brilliant idea!! Thanks so much for the insight, you’ve save my sanity.

 

[Drew76]

So I was able to check the wiring and my vehicle harness side matches up with the 2000 EWD I have for cali emissions, I also checked my 2000 parts truck Fed emissions wiring and it doesn't match up to yours either.... best to do what TheDurk suggested.

 

[gamefreakgc]

Getting a snipped connector won't help if I don't know how my vehicles wires to it. Also, I have a new connector shell, the wire pins are still fine. I just don't know what wire goes where on the connector.

Even more confusing is that I got someone to take a pic of their 2000 California AF wires and their colors are completely different than mine. I'm baffled.. how do I even proceed? My vehicle contradicts both wiring diagrams and another similar vehicle.

I guess I'm not understanding the issue well. I know the Cali emission vehicles are not as common and Toyota changed wire colors in the sub-generations of 96-98, 99-00, and 01-02 for various sensors and the ECU. But if you can find a vehicle with the same wire colors, just cut off the connector and use it for reference. The connector cannot be put on upside down or anything so you'll know exactly how it goes. I've done this before and it never fails me.

You're on track that the larger wires are the heater circuit though. Solid browns are grounds almost 100% of the time.