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Toyota Service
Toyota Service, Lexus and Toyota expert
Category: Lexus
Satisfied Customers: 4605
Experience:  30 + years of experience; Multiple Award Winning Svc Mgr; Just Answer Customer's Choice Award Winner
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I have a 2000 lexus ls430, the driver side upstream sensor

Customer Question

I have a 2000 lexus ls430, the driver side upstream sensor was ripped off and the harness needs rebuilding, I need to k now the order of the wires ,but the actual color order etc.seems the harness supply from the car which is the male side has four wires they are different colors...I pulled a used pigtale from another car that will work but I need to see which order they go...
Submitted: 8 months ago.
Category: Lexus
Expert:  Toyota Service replied 8 months ago.

Hello. Welcome to Just Answer. Please allow me to assist you. DO you know any of the wire colors on the vehicle harness for this sensor?

Customer: replied 8 months ago.
two are black one is tan and other is yellow and green
Expert:  Toyota Service replied 8 months ago.

On the harness side of the sensor wire connector:

The tan wire is the ground wire.

The yellow/green wire is the heater circuit (voltage is applied on cold starts).

There are 2 white wires...

one white wire has battery voltage (will disappear of you pull the 7.5 amp EFI #2 fuse)

The other white wire is the signal from the sensor to the computer

Customer: replied 8 months ago.
what r the black wires?I am refering to the harness side on the car.It runs with the transmission harness connector,.On the oxygen sensor it has 1 blue,1 white,and 2 black.I am trying to run the correct wires to from the car to the oxygen sensor.
Expert:  Toyota Service replied 8 months ago.

Exactly which sensor are you working with? I am understanding you to be working on the driver side of the car, the first sensor on the exhaust, is this correct?

Expert:  Toyota Service replied 8 months ago.

On your sensor, white is power in

blue is sensor input to the computer.

the 2 black wires are the heater circuit from the computer and the ground for the sensor heater.

Customer: replied 8 months ago.
absolutely...2000 lexus ls430
Expert:  Toyota Service replied 8 months ago.

I am sorry, but my L S wiring diagram does not show 2 black wires at the sensor connector. On nthis engine diagram, the sensor withthe blkack wire si for the side of the engine with cylinder one on it.

The black wire is signal to the computer from the sensor.

White is power into the sensor (for the heater)

Tan is ground

Yellow/green is the computer signal to activate the sensor heater.

Customer: replied 8 months ago.
I have tan wire on harness side to black wire on sensor side which are grounds, then yellow and green on harness side is for the sensor black wire which are both heaters signals,but I have to figure out what the other two black wires are on the harness side.
Expert:  Toyota Service replied 8 months ago.

I do not think that the other wires are for the sensor. You only have 4 wires to the sensor. Ground, signal, battery and heater circuit activation.

Customer: replied 8 months ago.
I know I was refering to male to female to pair up the four wires on each side.the sensor side has the 2 black and 1 white and one blue,I was just refering to which side color goes to what when I connect them.I want the heater circuit of the sensor to match heater wire from harness, and input to input,and ground to ground etc.
Expert:  Toyota Service replied 8 months ago.

what are your harness side colors? You should have a tan. That is ground. You should have a green/yellow. That is the wire that the computer turns on to activate the sensor heater coil. White is power into the sensor for the heater coil. Black is signal line from the sensor to the computer.

Customer: replied 8 months ago.
harness colors are tan,black,yellow/blue, and a large blue wire the harness has two black wires and one white and one blue

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