Now Voltage at O2 sensor on 1996 Toyota Land Cruiser?

It all the wiring system,that you have to check,where the voltage is getting dropped or any wiring is getting short.

First check if sensor is good.If its bad,old then replace the sensor.But if the sensor is good and still

No voltage to 02 sensor bank1 sensor 1.

Basically if sensor is faulty you get obd code P0135 error code.

So scan and check
Are you getting a specific malfunction code that indicate a
problem with one of the sensors?

If oxygen sensor bank 2 sensor is working then........

Try this connect bank 2 sensor wire to bank 1 and see if you get voltage at bank 1 or not.

Disconnect the oxygen sensor for bank one sensor one and check for voltage on the yellow wire with a red tracer you should have 12 V with the key in the on position?

Red/Yellow wire on the o2 sensor bank 1 sensor 1.

If not then check

Do you have power to the Y/R wire at the EGR VSV and the IAC motor?

The Y/R wire has multiple splice points and feeds the components I listed along with the rear sensor heater wire Y/R wire. It does not matter where the 12volts comes from unless there is high resistance in which case it affects current flow and the computer will see this and sets the code. Take a jumper wire from the battery and splice it to the Y/R wire at B1 S1 and see if the code goes away. If you monitor the voltage on the ground side IE the computer side that the ECU grounds it should drop to 1 to 2 volts then work its way up as the computer duty cycles the ground. Splice point E21 is suspect on the Y/R wire.

The voltage comes from the battery by way of the efi relay and several splice points. If there is high resistance in any of those it can affect several things. The heater element in the sensor receives 12 volts in then through the element and then out to the computer where the computer grounds the circuit and monitors current flow to determine if the circuit/heater is good. By taking a jumper wire from the Positive battery terminal to the Y/R while it is plugged in then monitoring the GRAY wire that goes back to the computer you check 2 things. The voltage through the heater and the computers ability to turn the ground side on?

This details will help you.Thanks.

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