primary 02 sensor ground help
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primary 02 sensor ground help
new member first post
please pardon my mistakes in regards to posting
my 2001 civic ex 5spd vtec has po135 for a while now
i have done some trouble shooting at my noob level
so far the 12 volts are present for the primary o2 sensor
also so confirmed at ecm black/yellow wire of a thicker gauge on a different ecm connector
but there is no ground at either engine side harness or o2 sensor plugin side
i have done continuity check test from engine harness plug the two heater wires test good for continuity
but if i put a test light to the engine side plug then the test light does not light up and every time i clear the p0135 dtc then have the car started but it keeps coming back within seconds
now if i do same thing and short the test light to chasis ground the test light works
i even repeated the same test clearing dtc and connecting test light directly to ecm but no go
so here i am searching for that ecm 02sensor ground source that seems mia
any help would be greatly appreciated
thanks to all members and readers
Last edited by sdaidoji; Jul 8, 2022 at 06:33 PM. Reason: user have a very unfriendlier attitude, striking though his untrue words - moderation team
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Thread Starter
Registered!!
Joined: Jul 2022
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From: earth
Rep Power: 0 Re: primary 02 sensor ground help
01-03 is regular sensor
04-05 is a/f wide band
Yes i am aware
But thats not my question
I am missing ground feed to the sensor
If there is no ground its not going to turn
On the heater
04-05 is a/f wide band
Yes i am aware
But thats not my question
I am missing ground feed to the sensor
If there is no ground its not going to turn
On the heater
Joined: Dec 2008
Posts: 15,176
Likes: 1,605
From: TN
Rep Power: 367 Re: primary 02 sensor ground help
I would recommend starting actually checking the wires. stripped insulation, etc
they are 21 years old, after vibrations and scrubbing for 21 years, they might have damage
they are 21 years old, after vibrations and scrubbing for 21 years, they might have damage
"Marge, anyone could miss Canada! All tucked away down there."
Joined: Feb 2016
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From: Barrie, ON Canada
Rep Power: 222 Re: primary 02 sensor ground help
There's a link to download the factory service manual. Sensor might ground to the ecm, not the engine ground.
Where did you get the sensor from? And how much was it?
We've seen fake sensors, and sometimes the sensor is bad out of the box
Where did you get the sensor from? And how much was it?
We've seen fake sensors, and sometimes the sensor is bad out of the box
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