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Heated Oxygen Sensor circuit failure

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Heated Oxygen Sensor circuit failure

Post by jeffc » Mon Sep 04, 2017 12:29 am

I have a code P0030 Heater circuit on front oxygen sensor. I had to get the code read at the local parts shop since my reader is kaput and I have no way of reading live data. With the heater circuit causing a cel will that shut down the 02 sensor all together and set the fuel mixture to a fixed value (open loop)? If I clear the codes it returns within the second restart.

2000 V70R

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Year and Model: 1999 V70 XC AWD 2.4T
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Re: Heated Oxygen Sensor circuit failure

Post by wizechatmgr » Mon Sep 04, 2017 12:44 am

The heated oxygen sensor may not get hot enough to give a valid reading (one the ECU expects to see) if the heater on it no longer functions.

You should be able to check the heater circuit on the O2 sensor with a multimeter set for ohms (resistance.) If it is infinite ohms, it is toast... If it isn't, then it's time to check the harness, power supply to it, fuses, etc.
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1999 V70 XC AWD - ~187k miles

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