My ogasnin d house. please i need your help with a diagnosis. Been doing little tune ups and maintenance on a 2001 toyota camry. Since the time i can remember, whenever I check the output voltage from the upstream O2 sensor I have always gotten a reading of 3.xx V. However, checking online I saw that the normal voltage shoud be between 0.1V and 1.0V at worse. Yesterday i got another O2 sensor just to confim, i got the same reading. Now the crazy thing is when i disconnected the O2 sensor, though the Check engine light came on (P1135 error code or so)... funny thing is ECM was still reporting a reading of 3.xx V even while the sensor was disconnected. Pls how do I resolve this? Where do I start from?

OgaKazeem:
My ogasnin d house. please i need your help with a diagnosis. Been doing little tune ups and maintenance on a 2001 toyota camry. Since the time i can remember, whenever I check the output voltage from the upstream O2 sensor I have always gotten a reading of 3.xx V. However, checking online I saw that the normal voltage shoud be between 0.1V and 1.0V at worse. Yesterday i got another O2 sensor just to confim, i got the same reading. Now the crazy thing is when i disconnected the O2 sensor, though the Check engine light came on (P1135 error code or so)... funny thing is ECM was still reporting a reading of 3.xx V even while the sensor was disconnected. Pls how do I resolve this? Where do I start from?

ECM reporting a reading with sensor disconnected. Are you sure ECM is fine?

oluwaseunla:


ECM reporting a reading with sensor disconnected. Are you sure ECM is fine?

baba i no even understand. i decided to disconnect the o2 sensor after i noticed exactly d same voltage on d new one I got (3.299v). wat r d chances 2 separate sensors give exactly d same voltage?

Defective o2, or Lambda sensors might still give the same voltage on an obd2 scanner ‘live data’ when unplugged..to ascertain if it works...hit the pedal a lil and ensure the rpm remains on 2,500. Check if there are constant changes on the voltage readings...if the readings are static, replace the sensor.
Regarding the 3.Bleep reading you always get...it’s pretty normal for a some vehicles to have such readings...kindly, ensure that you replace o2 sensors, with sensors having the same part numbers. Cheers.

OgaKazeem:
My ogasnin d house. please i need your help with a diagnosis. Been doing little tune ups and maintenance on a 2001 toyota camry. Since the time i can remember, whenever I check the output voltage from the upstream O2 sensor I have always gotten a reading of 3.xx V. However, checking online I saw that the normal voltage shoud be between 0.1V and 1.0V at worse. Yesterday i got another O2 sensor just to confim, i got the same reyading. Now the crazy thing is when i disconnected the O2 sensor, though the Check engine light came on (P1135 error code or so)... funny thing is ECM was still reporting a reading of 3.xx V even while the sensor was disconnected. Pls how do I resolve this? Where do I start from?

Don't get yourself confused ,what you need the basic operation ubderstanding .
there are two types of O2 sensor narrow band and wide band .Narrow band typically switch from 0V to 1V to react to air fuel mixture variation and relies on voltage solely to achieve this whereas wideband sensor uses current to follow air fuel variation and the small 3.3V -3.*** V voltage margin is used to represent the wide margin of current fluctuation(this might sound a little bit complicated) which is why the voltages fluctuation is small.
Toyota is one of the early adopter of wideband O2 sensor so that which is the reason for your car 3.×× v values ranges ,it is using current internally to respond to air fuel ratio variation but voltage can only varies in corresponding small step to depict this.
The ecu uses the sensor current variation to make fuel trim adjustment and diagnosis .
From my own practically experience ,the sensor voltage stays between 3.3v -3.28v when the sensor is not working regardless of various instances of fuel and air variation .
The voltage can peak up to 5V at extreme lean condition and go as low as 2V when fully rich but stays around 3.28v -3.21v at idle condition which is totally a different rules u get in narrow band ones that you read about in books and YouTubes.
I will soon upload some live practical pids pix when I am less busy

autologic:

Don't get yourself confused ,what you need the basic operation ubderstanding .
there are two types of O2 sensor narrow band and wide band .Narrow band typically switch from 0V to 1V to react to air fuel mixture variation and relies on voltage solely to achieve this whereas wideband sensor uses current to follow air fuel variation and the small 3.3V -3.*** V voltage margin is used to represent the wide margin of current fluctuation(this might sound a little bit complicated) which is why the voltages fluctuation is small.
Toyota is one of the early adopter of wideband O2 sensor so that which is the reason for your car 3.×× v values ranges ,it is using current internally to respond to air fuel ratio variation but voltage can only varies in corresponding small step to depict this.
The ecu uses the sensor current variation to make fuel trim adjustment and diagnosis .
From my own practically experience ,the sensor voltage stays between 3.3v -3.28v when the sensor is not working regardless of various instances of fuel and air variation .
The voltage can peak up to 5V at extreme lean condition and go as low as 2V when fully rich but stays around 3.28v -3.21v at idle condition which is totally a different rules u get in narrow band ones that you read about in books and YouTubes.
I will upload some live practical pids pix when I am less busy

baba I swear U r d best. i eventually got to understand d reason I was getting dt reading.
U r very correct on d current/voltage issue. regardless of wats happening i was always getting 3.299V. i don almost go wash d ECU for insyd omo o .... hehehe.... bro thanks again. based on dis knowledge i can further my research on d issue.

ok sir can I ask this. i noticed voltage on d downstream sensor is abt 0.4 - 0.7V. i believe this one is a narrowband sensor right? now my question is can a person use narrowband sensor to replace d upstream (wideband) sensor?

OgaKazeem:


now my question is can a person use narrowband sensor to replace d upstream (wideband) sensor?

How can narrow band and wide band be interchangeable?
To make things simple

Do yourself favor, if the part numbers are not the same, don't bother.

One is an ordinary regular oxygen sensor.

The other is an air fuel ratio sensor.

To make things technical and complicated

But if you want to know how the technology works then go ahead with this https://www.hamotorsports.com/what-is-a-wideband.html

i noticed voltage on d downstream sensor is abt 0.4 - 0.7V. i believe this one is a narrowband sensor right
Yes cos the primary reason for the downstream is for catalyst monitoring ,fuel management is secondary (upstream is basically fuel management) and using wi
de band for such purpose will not be cost effective (wide band is more sophisticated and expensive) when narrow can readily serve the purpose .
I am yet to see a a manufacturer that will wide band for downstream !!
now my question is can a person use narrowband sensor to replace d upstream (wideband) sensor?
No Sir ,unless you want to change to ecu that support narrowband upstream like the 1999 downward model which just like downgrading your fuel management to worse than before .
Upstream is upgrade of narrowband for better fuel management and to achieve near zero emission standard .

AutoElectNG:




How can narrow band and wide band be interchangeable?
To make things simple

Do yourself favor, if the part numbers are not the same, don't bother.

One is an ordinary regular oxygen sensor.

The other is an air fuel ratio sensor.

To make things technical and complicated

But if you want to know how the technology works then go ahead with this https://www.hamotorsports.com/what-is-a-wideband.html

exactly my thought bro. requested for upstream and downstream O2 sensors. was given 2 sensors. one with a long wire another with short wire I assumed dey were up and downstream until I checked them against spec on AllData behold dey were both downstream. went back to return seller refuses to collect. and i cnt start shouting with him. dts d reason I asked if there was a way to make it work.... thanks for the clarification AutoElectNg.

autologic:
i noticed voltage on d downstream sensor is abt 0.4 - 0.7V. i believe this one is a narrowband sensor right
Yes cos the primary reason for the downstream is for catalyst monitoring ,fuel management is secondary (upstream is basically fuel management) and using wi
de band for such purpose will not be cost effective (wide band is more sophisticated and expensive) when narrow can readily serve the purpose .
I am yet to see a a manufacturer that will wide band for downstream !!
now my question is can a person use narrowband sensor to replace d upstream (wideband) sensor?
No Sir ,unless you want to change to ecu that support narrowband upstream like the 1999 downward model which just like downgrading your fuel management to worse than before .
Upstream is upgrade of narrowband for better fuel management and to achieve near zero emission standard .

How can I easily identify upstream from downstream sensors so as not to make the same mistake I made earlier...?

Ideally use part numbers to buy.

If using sight, the nigerian standard, then take along samples, compare everything must be a match, as far as the inscriptions on the body of the sensor are concerned

If you follow the international standard that is part numbers, and don't purchase knockoffs from substandard dealers, you will be fine.

autologic:

Don't get yourself confused ,what you need the basic operation ubderstanding .
there are two types of O2 sensor narrow band and wide band .Narrow band typically switch from 0V to 1V to react to air fuel mixture variation and relies on voltage solely to achieve this whereas wideband sensor uses current to follow air fuel variation and the small 3.3V -3.*** V voltage margin is used to represent the wide margin of current fluctuation(this might sound a little bit complicated) which is why the voltages fluctuation is small.
Toyota is one of the early adopter of wideband O2 sensor so that which is the reason for your car 3.×× v values ranges ,it is using current internally to respond to air fuel ratio variation but voltage can only varies in corresponding small step to depict this.
The ecu uses the sensor current variation to make fuel trim adjustment and diagnosis .
From my own practically experience ,the sensor voltage stays between 3.3v -3.28v when the sensor is not working regardless of various instances of fuel and air variation .
The voltage can peak up to 5V at extreme lean condition and go as low as 2V when fully rich but stays around 3.28v -3.21v at idle condition which is totally a different rules u get in narrow band ones that you read about in books and YouTubes.
I will soon upload some live practical pids pix when I am less busy

Please I need expert opinion on a car I want to buy. It’s a Toyota Matrix. I scanned the car and this code came out p0012 camshaft position sensor Bank 1. Should I run away? Please help

AutoElectNG:
Ideally use part numbers to buy.

If using sight, the nigerian standard, then take along samples, compare everything must be a match, as far as the inscriptions on the body of the sensor are concerned

If you follow the international standard that is part numbers, and don't purchase knockoffs fr substandard dealers, you will be fine.

Please I need expert opinion on a car I want to buy. It’s a Toyota Matrix. I scanned the car and this code came out p0012 camshaft position sensor Bank 1. Should I run away? Please help

Just an aside to others that may be reading with while scratching their head.

What is happening here is not the norm but an exception. You shouldn't normally have to become an electrical engineer with a tester to work on your cars systems.

Most modern cars will indicate a faulty o2 sensor by a specific code. Simple remove and replace the identified sensor with one from a good brand and source. I swear by Bosch but there are others.

I like to encourage DIY on here.

DukeNija:


Please I need expert opinion on a car I want to buy. It’s a Toyota Matrix. I scanned the car and this code came out p0012 camshaft position sensor Bank 1. Should I run away? Please help

It's a Toyota. They've been making vehicles since at least the 60's.

This modern car has hinted to you what could be wrong. Call around to mechanics and ask them how much to fix. Consider that cost in your negotiations if everything else meets your standard in the car.

DukeNija:


Please I need expert opinion on a car I want to buy. It’s a Toyota Matrix. I scanned the car and this code came out p0012 camshaft position sensor Bank 1. Should I run away? Please help

This code points to either an electrical mechanical or hydraulic fault.

Only diagnosis and physical inspection with confirm.

A vehicle had this code, the client told me he was told he would need a new engine, I said I disagreed, that it was more likely electrical or mechanical or hydraulic and that the problem is common to Toyota Corolla and Matrix.

It is very likely an electrical issue can hydraulic pressure with the VVT system.

Or a hydraulic issue causing electrical problems.

If you are in Lagos, get radautoworks take a look at it.

They solved it, it was an electrical fault.

I don't think it is a major problem, but then that's just a thought, I haven't had a look.

AutoElectNG:
Ideally use part numbers to buy.

If using sight, the nigerian standard, then take along samples, compare everything must be a match, as far as the inscriptions on the body of the sensor are concerned

If you follow the international standard that is part numbers, and don't purchase knockoffs from substandard dealers, you will be fine.

alryt bro. thanks alot.

OgaKazeem:


How can I easily identify upstream from downstream sensors so as not to make the same mistake I made earlier...?

Use part number

autologic:
Use part number

gorrit boss... tnx

DukeNija:


Please I need expert opinion on a car I want to buy. It’s a Toyota Matrix. I scanned the car and this code came out p0012 camshaft position sensor Bank 1. Should I run away? Please help

Not a good decision to use a mere scan DTC to make judgement if a car is good or not for purchase .Get an expert to do a complete inspection check for you.

autologic:

Not a good decision to use a mere scan DTC to make judgement if a car is good or not for purchase .Get an expert to do a complete inspection check for you.

The decision to scan the car is because of past experiences where a mechanic was unable to detect some faults. I believe it’s important to support the physical and mechanical inspection with scanning. But thanks all the same.

DukeNija:


The decision to scan the car is because of past experiences where a mechanic was unable to detect some faults. I believe it’s important to support the physical and mechanical inspection with scanning. But thanks all the same.

The car was a corolla.

corolla and Matrix are twins.

It had this same code.

Problem was electrical.

Vehicle was very sluggish.

The problematic electrical component was replaced.

And the code disappeared.

Following your post I asked again

Client responded that the code is gone for good and has not resurfaced.

Over a month later.

My point is it a diagnosis is key to zero in on electrical, hydraulic or mechanical causes.

It is not always caused by sludge

DukeNija:


The decision to scan the car is because of past experiences where a mechanic was unable to detect some faults. I believe it’s important to support the physical and mechanical inspection with scanning. But thanks all the same.

The inspection should have included said scan if done properly. Who inspected it?

radautoworks:


The inspection should have included said scan if done properly. Who inspected it?

My Kazeem did. The car drove well but I had to be sure so we scanned it. And that was the only code that came up. I’m more concerned about the cars engine.

AutoElectNG:


The car was a corolla.

corolla and Matrix are twins.

It had this same code.

Problem was electrical.

Vehicle was very sluggish.

The problematic electrical component was replaced.

And the code disappeared.

Following your post I asked again

Client responded that the code is gone for good and has not resurfaced.

Over a month later.

My point is it a diagnosis is key to zero in on electrical, hydraulic or mechanical causes.

It is not always caused by sludge

Hmmmnn. Oh well, I guess I’ll have to search for another car cos I sort of moved on from that car. I really wouldn’t want to gamble with a bad engine. I’d rather the issue is elsewhere.

DukeNija:


Hmmmnn. Oh well, I guess I’ll have to search for another car cos I sort of moved on from that car. I really wouldn’t want to gamble with a bad engine. I’d rather the issue is elsewhere.

Freedom of choice....you acted well within your rights...Godspeed