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Please Help With Diagnosis by OgaKazeem(m): 7:56pm On Aug 25, 2018 |
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? |
Re: Please Help With Diagnosis by oluwaseunla(m): 8:18pm On Aug 25, 2018 |
OgaKazeem: ECM reporting a reading with sensor disconnected. Are you sure ECM is fine? |
Re: Please Help With Diagnosis by OgaKazeem(m): 8:28pm On Aug 25, 2018 |
oluwaseunla: 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? |
Re: Please Help With Diagnosis by Alvin007: 6:09am On Aug 26, 2018 |
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. |
Re: Please Help With Diagnosis by autologic: 8:26am On Aug 26, 2018 |
OgaKazeem: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 1 Like |
Re: Please Help With Diagnosis by OgaKazeem(m): 10:34am On Aug 26, 2018 |
autologic: 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? |
Re: Please Help With Diagnosis by AutoElectNG: 11:09am On Aug 26, 2018 |
OgaKazeem: 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 1 Like |
Re: Please Help With Diagnosis by autologic: 11:12am On Aug 26, 2018 |
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 . |
Re: Please Help With Diagnosis by OgaKazeem(m): 11:52am On Aug 26, 2018 |
AutoElectNG: 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. |
Re: Please Help With Diagnosis by OgaKazeem(m): 5:39pm On Aug 26, 2018 |
autologic: How can I easily identify upstream from downstream sensors so as not to make the same mistake I made earlier...? |
Re: Please Help With Diagnosis by AutoElectNG: 5:43pm On Aug 26, 2018 |
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. 1 Like 1 Share |
Re: Please Help With Diagnosis by DukeNija(m): 6:49pm On Aug 26, 2018 |
autologic: 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 |
Re: Please Help With Diagnosis by DukeNija(m): 6:49pm On Aug 26, 2018 |
AutoElectNG: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 |
Re: Please Help With Diagnosis by Nobody: 6:53pm On Aug 26, 2018 |
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. 3 Likes |
Re: Please Help With Diagnosis by Nobody: 6:59pm On Aug 26, 2018 |
DukeNija: 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. 2 Likes |
Re: Please Help With Diagnosis by AutoElectNG: 7:16pm On Aug 26, 2018 |
DukeNija: 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. 1 Like |
Re: Please Help With Diagnosis by OgaKazeem(m): 7:32pm On Aug 26, 2018 |
AutoElectNG: alryt bro. thanks alot. |
Re: Please Help With Diagnosis by autologic: 7:59pm On Aug 26, 2018 |
OgaKazeem:Use part number |
Re: Please Help With Diagnosis by OgaKazeem(m): 8:33pm On Aug 26, 2018 |
autologic:gorrit boss... tnx |
Re: Please Help With Diagnosis by autologic: 2:25am On Aug 27, 2018 |
DukeNija: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. 1 Like |
Re: Please Help With Diagnosis by DukeNija(m): 4:37am On Aug 27, 2018 |
autologic: 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. |
Re: Please Help With Diagnosis by AutoElectNG: 5:58pm On Aug 27, 2018 |
DukeNija: 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 |
Re: Please Help With Diagnosis by radautoworks: 7:13pm On Aug 27, 2018 |
DukeNija: The inspection should have included said scan if done properly. Who inspected it? |
Re: Please Help With Diagnosis by DukeNija(m): 12:26am On Aug 28, 2018 |
radautoworks: 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. |
Re: Please Help With Diagnosis by DukeNija(m): 12:31am On Aug 28, 2018 |
AutoElectNG: 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. |
Re: Please Help With Diagnosis by AutoElectNG: 7:27am On Aug 28, 2018 |
DukeNija: Freedom of choice....you acted well within your rights...Godspeed 1 Like |
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