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jaswood
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P135, bank 1 sensor 1 oxygen sensor heater open. Verified with multimeter plus bank 2 sensor 1 measured 14 ohms, should be 5-6 ohms.

Not sure that means heater is a problem. Unless you nulled the multimeter to net out the test leads of the meter and of the harness you could be getting a false reading. Typically heaters (resistors) fail to an open circuit so a failed heater would read infinity or very high impedance.

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P135, bank 1 sensor 1 oxygen sensor heater open. Verified with multimeter plus bank 2 sensor 1 measured 14 ohms, should be 5-6 ohms.

Not sure that means heater is a problem. Unless you nulled the multimeter to net out the test leads of the meter and of the harness you could be getting a false reading. Typically heaters (resistors) fail to an open circuit so a failed heater would read infinity or very high impedance.

Fluke digital multimeter and I always touch the leads together to verify zero ohms reading.

Electronic training began in 1957 in the USAF.

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I agree the heater is probably not bad, However a new O2 wont hurt....

On what basis..?

Pins 1 and 2 of driver's side sensor reads open, same pins on passenger side sensor reads ~14 ohms, shop manual calls for ~5-6 ohms at 70F.

If the one sensor didn't read open I would probably ignore the 14 ohm reading as the engine ECU isn't complaining about that.

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from this web page: http://www.autozone.com/autozone/repairguides/Electronic-Engine-Controls/Oxygen-Sensor/_/P-0900c1528026a717

WARNING

The four wire Heated Oxygen (HO2) Sensor have two separate circuits, the signal circuit and the heater circuit which must not be confused. Never apply voltage to the signal wiring of a HO2sensor, otherwise it may be damaged. Also, never connect an ohmmeter (or a DVOM set on the ohm function) to both of the signal wires of a HO2sensor at the same time, otherwise the sensor may be damaged.

Not sure if this is a concern for all DVMs but the DC current used in the Ohms readings can damage the sensor side of the device so these folks state. Fine for the heater side.

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You know sometimes the heaters are wired in series, once one is open both are open....however the sensor itself will function once heated up....

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You know sometimes the heaters are wired in series, once one is open both are open....however the sensor itself will function once heated up....

I don't think so. When there is a heater it is pulling about 30 Watts of power. That current (>2 Amps) couldn't flow through the sensor without major damage. The two wire Oxygen sensors are just a sensor element only. They count on exhaust vapors to heat up sensor. The heater is primarily to speed up the engine getting into closed loop operation and to keep sensor warm in idling conditions where it could cool too much.

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from this web page: http://www.autozone.com/autozone/repairguides/Electronic-Engine-Controls/Oxygen-Sensor/_/P-0900c1528026a717

WARNING

The four wire Heated Oxygen (HO2) Sensor have two separate circuits, the signal circuit and the heater circuit which must not be confused. Never apply voltage to the signal wiring of a HO2sensor, otherwise it may be damaged. Also, never connect an ohmmeter (or a DVOM set on the ohm function) to both of the signal wires of a HO2sensor at the same time, otherwise the sensor may be damaged.

Not sure if this is a concern for all DVMs but the DC current used in the Ohms readings can damage the sensor side of the device so these folks state. Fine for the heater side.

IMMHO it would take a seriously high voltage, hi-pot "arc" level most likely, to do any damage to the oxygen sensor itself.

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P135, bank 1 sensor 1 oxygen sensor heater open. Verified with multimeter plus bank 2 sensor 1 measured 14 ohms, should be 5-6 ohms.

Not sure that means heater is a problem. Unless you nulled the multimeter to net out the test leads of the meter and of the harness you could be getting a false reading. Typically heaters (resistors) fail to an open circuit so a failed heater would read infinity or very high impedance.

Proper reading is per Lexus manual.

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