₦airaland Forum

olaboy1:
I am getting a conflicting report on the ohms for the downstream sensors.
FSM m_05_0092 is saying the specified ohms condition reading should be 5 to 10 ohms for P0141, and m_05_0057 for P0161 is saying 11-16ohms.

m_05_0092 deals with 1AZ-FE engines running the SFI SYSTEM
m_05_0057 deal with 1AZ-FE engines running the EFI SYSTEM.

From your user manual, which one does your vehicle run?

That will determine which values are appropriate?

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MODIFIED BELOW
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Study both documents in their entirety, subtle differences exist, especially in/around the following:

1. heater resistance results are different
2. EFI relay position is different
3. EFI relay design is different

The key to determine which system your ride uses is to study the EFI RELAY POSITION, then you will know which of the two documents to follow!

olaboy1:
I can't buy the sensors from USA because they don't have Avensis verso in USA.
I will look around Europe where I can get them cheaper

They don't have Avensis Verso in America true

BUT

Toyota used the 1AZ-FE engine in several vehicle besides the above.

Just run a part number search beginning with Amazon to see if you actually cannot find it cheaper in America

SmartchoicesNG:
I have a car whose obd2 plug cables have been cut... How can I reconnect them?

Full description of the car so we know what the patient is, and how to approve this case!
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MODIFIED BELOW
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how to approach this case!

olaboy1:
I am getting a conflicting report on the ohms for the downstream sensors.
FSM m_05_0092 is saying the specified ohms condition reading should be 5 to 10 ohms for P0141, and m_05_0057 for P0161 is saying 11-16ohms.

Valid observation.

Independently verified.

While we attempt to clarify this, please go-ahead to purchase the upstream sensors

olaboy1:
I really want to make sure the downstream sensors are in good working condition because they are the most expensive quotation I got from Toyota.
The upstream sensors no doubt I'm gonna shop for those brand new OEM from Toyota. Everything costs almost 2 times here in Europe compared to USA. My 4 sensors are like $1150 where as in the states they probably cost around $600 for the 4.

My downstream sensors passed the test in the video you posted.

Do I need a propane gas or kitchen gas voltage tests for the downstream sensors?
I read the voltage for the downstream sensor doesn't oscillates, it stays stable
I am still interested in the FSM that specifically shows and explains changing of sensors in this car. Just like it shows in the body repairs, it's so explanatory.

Buy them from America, they will be cheaper, freight inclusive. Unless your calculations prove otherwise, then you are stuck.

We want to assume that the upstream sensors had been changed but the downstream are stock from factory, if that is the case, they are tired. Oxygen sensors don't last forever.

Even if it reads well, but it has become less sensitive, it can give the ECM information that it considers suspect and so it still sets up a code or might be sluggish.

At over 200,000 kilometers, you should seriously consider replacing them all

Infographic source: http://www.buyautoparts.com/howto/oxygen-sensor-life-expectancy.htm

Here is a second opinion: http://www.ngkplugpro.ca/content/contentfiles/pdf/NTKO2-0308-1LifeExpectancyofOxygenSensors.pdf

olaboy1:
P0161 ends with 27 and not 29 from m_05_0018
P0141 ends with 27 also from m_05_0018
What do we make out of this.

Non-issue - unwrap and check wire connections as above

olaboy1:
See pixs

Carefully unwrap the electrical tape and check for any of two wires making contact with each other and repair such an abnormality

Figure 1 and 2 referenced in earlier posts

No electricals/electronics - no modern day vehicle!

In other news.

Why should the car owner care about OBD II?

We are going to cut and paste some material here to help answer that question!

All material posted courtesy The Vector Congress Stuttgart,Germany

olaboy1:
How do we proceed.

Provide results of tests 2 - 4 of the m_05_0057 file

olaboy1:
Are the downstream sensors part number specific, what I mean is I have two part numbers 89465-44050 and 89465-44060 for the 2 downstream sensors, are they bank specific or it doesn't matter which banks I put them as long as they are installed after the CAT.

Downstream sensors (89465-44050 and 89465-44060)
Bank 1 sensor 2: 13.9ohms and I got beep for continuity
Bank 2 sensor 2: 13.2ohms and I got beep for continuity

I will do a voltage test for them later by using kitchen gas to heat them up and watch how voltage drops and go up with introduction and removal of heat.

Do I still need to test the upstream sensors since they don't meet manufacturer's part number spec.

Yes they tend to be application specific. So we don't recommend switching them.

How do the results you have obtained compare to what the manual states the outcome ought to be?

No need to test the upstream sensors, all you need to do is to replace them!

The earlier response to test all 4 was hurriedly drafted, after taking time to check out your responses, it is unnecessary.

olaboy1:
I have the sensors now.
Upstream sensors
Bank 1 sensor 1: 89465-20790
Bank 2 sensor 1: 89467-42020
Downstream sensors
Bank 1 sensor 2: 89465-44050
Bank 2 sensor 2: 89465-44060

Toyota manufacturer's specification
Upstream sensors 1 (89465-42020 |-| 89465-44030)
Downstream sensors 2 (89465-44050 |-| 89465-44060)

All the 4 sensors I pulled out from my car have electrical black tape they have used to connect the sensors to the connectors, I thought the sensors are supposed to be plug and play if they are manufacturer's spec for this car. I need to find out from the old mechanic what exactly happened.
Also remember I told you my car runs on a petrol engine and the engine Idles like a Diesel engine. When the two upstream sensors were taken off and I started the car, that Diesel engine sound increased by 25%, and finally when the 2 downstream sensors were taken off the Diesel engine sound increased by 50% more like a car without an exhaust. This makes me to feel my car is suffering from sensor problems.
How do we proceed.

For every application, we have exact fit and universal, universal involves wire splicing. Sadly, in your case, the wrong sensors were used so they are not even a fit, so must be replaced.

Are you sure you don't have an exhaust leak or exhaust manifolds improperly tightened?

No point starting the car with the sensors off!

olaboy1:
The sensor wires were actually cut to replace them with the brand new sensors that didn't come with any connectors.
One of the wrongly replaced upstream sensors 89465-20790 had a wrong Volvo sensor with part number 8202209 CEN523310 there before.

So it looks like we have two wrong upstream sensors.
The downstream sensors seem to be the spec for my car and maybe that's why I didn't get DTC P0141 Bank 1 sensor 2, but I got DTC P0161 for Bank 2 sensor 2.

Let me know if you need more information

That is because those were not an exact fit.

Right now it is clear that you need to purchase two upstream sensors with the right part numbers.

So the only test you need to conduct as shown in that video is on the sensor responsible for P0161, but given the age of the vehicle and a lack of knowledge as to previous maintenance practices, and the need to start on a clean slate, it is highly recommended that you consider purchasing all four and replacing all four but you can keep the sensor that would otherwise have caused a P0141 DTC to be set if it were bad, but that isn't.

All the same can you please conduct that test on the sensor responsible for P0161, so we have be conclusive on the state/status of that sensor?

apply the test conducted in the last video and paste the results here

tunde783:
how do u mean?
pls explain in layman terms.

https://www.nairaland.com/3661728/on-board-diagnostics-obd-ii-questions/3#54612233 Explains monitors

Applying the concept to your problem P0016
https://www.nairaland.com/3661728/on-board-diagnostics-obd-ii-questions/5

olaboy1:
Alright I will skip the continuity test for the wire harness for now since if I follow the FSM I might need very long wires to get the DMM to reach.
I have been to Toyota company now service department and I now have the sensor manufacturer's spec and requirements.
They told me it's not possible to have all my sensors go bad at once, but I am curious to find out what the real problem is with this car.

Upstream A/F sensors Denso OEM
89465-42020 ---------->89465-44030
Downstream oxygen sensors
89465-44050 ----------->89465-44060

One of my upstream sensors bought by my old mechanic is reading Denso 89465-20790, this is why it's very good to take control of the management of your stuffs. Imagine if this was an aircraft and a poor mechanic judgment and call on spare parts would be a colossal loss of lives.

So I am moving on to step 2 to do 100% sensor checks. You can see this is an eye opener that even though the upstream sensor is Toyota and Denso and has the proper ohms reading for a downstream sensor, putting it in my car as a downstream sensor would still not work.
Hence why I need to check the sensor part numbers, correct readings don't equal right sensors.

Awaiting feedback!

olaboy1:
There are 4 stages of this troubleshooting.
1. ECM
2. Sensor
3. Wire harness
4. Relay

According to the FSM, for the downstream that is true.

It appears not to be true for the upstream.

I have done 1, I want to skip 2 for now because I want to take all the sensors out from the CAT to check if I can find the part numbers and manufacturers names on them, just to 100% ascertain that I have the right sensors installed on this car.

Good move. But proper organization is a must so you don't mix them up

So I am thinking of checking all the 4 wire harnesses for continuity. Do I need a voltage test at the connector side of the wire harness that plugs into the sensor connector (by voltage test on the wire harnesses I mean when it's connected to the ECM with the ignition ON). I want to know if indeed the 11.9v coming from the ECM under the pigeon hole actually travels through the wire harness up to its connector in the engine bay.

What you need if you want to check the wire harnesses for continuity is a resistance test, remember continuity means current flows, if current can flow, forget voltage test, you are already covered, guess why? Study the relationship between current and voltage!

You don't want to fry the ECM, so you must disconnect the battery, and disconnect the harness from the ECM. If it passes the continuity test between the sensor connector and the ECM connector, the ECM can command the sensor. Since a fault at the ECM end has been ruled out.

Electronics are delicate, please don't try this test with the ignition on and the battery connected!


Better be safe than sorry!

You might have to take some notes to map each of the 4 wires of the oxygen sensor to the respective pins at the ECM and we can bet your multi-meter pins are not long enough, so you will need extensions.

Remember to disconnect the battery when doing this test!

Once I am able to eliminate 1 and 3, I can then go ahead and take out the oxygen sensors of course I already know one of the upstream sensors is the wrong one. I don't know the history of the oxygen sensors in this car, so pulling them out and making sure they are manufacturer's spec will help me to move in the right direction to the next culprit. I am going to see a dealer and ask about the part numbers.
[/qoute]
Cool
[quote]I have been looking at our local used parts website for this car make, model and year, and two part numbers kept popping up.
89465-44050
89465-44060

What's your take on this. I am particular on taking the sensors out because I have seen several videos of people stuck because they didn't realize they have the wrong sensors in the car. It's difficult to do any visual inspection of the sensors without taking them out.

Good move!

layifioren:
Considering you have made up your mind to keep the vehicle, I will highly recommend you get the transmission rebuilt by a reputable mechanic that will offer you good warranty than to do a swap. I love Acuras die and I was a proud owner of 2002 and 2003 TL Type S and later on 2006 TL. Buying a used Honda transmission is a big gamble because there is no way to tell if the transmission is good except you test it on the donor vehicle before it's removed. From multiple experiences, I will never advice someone to buy a used Honda automatic transmission betweenyears 1998-2005 considering their astronomical failure rate. If you do find one with less than 80000 miles/ 1280000 km, then it might be worth buying. Anything more than that, for the sake of your wallet, don't do it. I am speaking from multiple experiences.

In other words, that is almost synonymous with import it because they don't provide mileage for engines and transmissions in local markets!

Unless he is fortunate to meet a vehicle that was scraped due to accident

olaboy1:
Thanks for the clarification. I have now done the voltage test correctly at the ECM connector using back probe pins and ignition ON, I have 11.9v in all the FSM directives for P1135/P1155/P0141/P0161.FSM requirement is 9-14v
So I guess we can rule out a bad ECM at this stage.
Within first 1-2 mins of starting my car, I had so much water gushing out from the exhaust like you are trying to wet some flowers with a hose and then it stops after engine is properly warmed up with just drops of water and not gushing of water.

Good job, we are getting there!

We have now confirmed that the ECM can indeed control the control the heater circuit, but when it attempts to, it encounters and abnormality!

To troubleshoot P1135/P1155, the next step is to investigate the sensor for this abnormality.

Remember that our analysis pointed to a bad heater circuit

This video will help you check the sensor to determine if it is good, if it is not good, then it has to be replaced! And then the monitors will give it a pass!!


https://www.youtube.com/watch?v=_Kr-c8eBl5E

Do the same thing for Bank 1 sensor 1 and Bank 2 sensor 1

olaboy1:
Awesome. I think continuity tests for the oxygen sensors will not destroy delicate electronics because the sensor connector is disconnected from the battery supply, sensor is hooked only to the CAT, so it's almost like bench testing.

Correct but to avoid voltage spikes and attendant consequences,good practice dictates disconnect battery before any work on vehicle circuits, example disconnecting the oxygen sensor connector from the oxygen sensor itself

The continuity test for the wire harness also from the FSM directives will not destroy any electronic components since you also need to disconnect the wire harness connector to the ECM that supplies it battery voltage.

Correct, but see note above.

Also note for continuity test you don't have the ignition ON, so I suppose there will be no battery voltage powering any sub-system or components that are designed to have power only when the ignition is ON. I hope I am making some sense, if not kindly give your opinion.

making sense but many systems have what is called Keep Alive Memory, also it is not entirely true that because the ignition is not on that there is no battery voltage!

In some cars, without the ignition being turned on the radio works!

Follow best practice in note 1 above if you want to be safe not sorry.

As for the ECM working or not, when I wanted to test for voltage and pulled out E10 connector and then put the ignition ON, the 2 radiator fans come on without starting the engine. When I put the E10 connector back the fans don't come on with the ignition on ON position, so I am thinking if connecting and disconnecting the E10 connector from the ECM can put the radiator fans ON/OFF doesn't that mean the ECM and that specific connector is doing its job. It's one of the connectors for the downstream sensor. So if it can control the fan properly, it should control the sensor since they are both on the same 'plug in' but of course different pins/terminals.

The thing about the fans is normal! Experienced same before more than once! To prove it, reconnect the connector and turn on the ignition, and the fans will not turn on!

Guess you did not disconnect the battery hence this, that is not correct protocol!

I hope the ECM is only in a fail safe mode and not destroyed. Changing ECM seem to be another ball game entirely as regards to VIN, keys and and other vital car information stored in the car's ECM.

a component in the ECM can fail and yet the car can run, if it not an absolute must component for the ride to drive.

Gotten great difficulty obtaining the part numbers for your ride, but still searching.

Worst case scenario, you might have to contact the dealer for the part numbers

mmrius:
The truth is after 3 days of driving around Lagos trying to get the cleanest MDX, this was the best I came across. Carfax report gives it a clean bill of health.

No major accidents or issues. All maintenance and service done accordingly.

At the time of purchase, there was no check engine light on. Although, it came on, on my way home. It's obvious the dealer had cleared all the error codes. Truth be told, the SUV is very clean through and through, the only but is this transmission wahala.

Ur best solution is have a good mechanic change ur transmission. Next time do not buy a car with check engine or any other warning lights on. Or go with a scanner when buying a car, at least know the pending faults the car has and if it is something minor then u can buy.

I see lots of cars for sale in autos section with check engine, abs and sometimes srs light on and yet the seller will call the car super clean perfect condition. Smh.

Next time you want to buy a car, don't be content with a scan.

Get a scan from a factory level scan tool for that ride or a professional aftermarket scan tool that can read all kinds of codes not just generic codes.

Next study how the monitors for that are activated. Next go on a test drive with a helper who will ensure that your test drive activates those monitors, compare and contrast the scan at the dealer stand with the test drive after the monitors have been run.

You can learn more about monitors here: https://www.nairaland.com/3661728/on-board-diagnostics-obd-ii-questions/3#54612233

This does not dismiss the need for a thorough physical inspection from top, bottom, sides and interior.

And the need to go with a professional, but let us hope the professional does the right checks, so a little knowledge on your side never hurts.

If any codes were cleared, they shall return and the truth will set you free!

olaboy1:
Yes I know your reply was for Tunde, but it seem to be somehow related to my car's problem.
I have read and watched YouTube video and now understand what they mean by a self test and monitors. I think that's also a reason why people say drive your car around like 20 mins before you go in for emission test especially in a very cold place like Scandinavia.

I inspect my current car in the middle of winter base on the reg num, and the guys would fire up the rpm for some minutes, guess they wanted it to be completely ready for the emission test, sometimes they do this for like 5-10mins. Inspection center is like 5 mins to my house.
So I can't say for sure how the former test was done, and hope the self test not performed has nothing to do with an OBD problem or other electrical faults.

I have now seen a YouTube video on hooking up a scanner to know exactly what monitors or self tests are not performed and the drive cycle sequence to follow to correct that.

I know you've written about taking out the battery cable when checking electrical components with a DMM, but how can one check for voltage if the battery terminal is taken off.



https://www.youtube.com/watch?v=lIgMOAIWzEU

The bolded did not apply to voltage tests, but to continuity checks. if you don't you get flawed results, can even destroy delicate electronics.

Your ECM is working so far, that is why it has gone into fail-safe mode, its self-test checks still run, we want to change the test conditions so that the ECM can give the oxygen sensor sub-systems a pass instead of a fail, that is the whole essence of what we have been doing about the P1135,P1155 and P0161

Location?

olaboy1:
"The monitors have to run" is that the same thing as the "self test not performed" I got on my vehicle.
How do I know myself that my car does not perform an OBD self test, and if that is true how do I make everything 100% right.

Actually responding to Tunde783

So far you are on track with the diagnosis

tunde783:
he told me he can't fix it , from research i have done, my timing belt was not properly fixed.

belt or chain?

tunde783:
all we did was to service the injector nozzle and bought a new fuel pump.
though i have been scanning for 3days now to see if other 11dtc would still come up, only p0016 is there now.

The monitors have to run before you can absolutely declare that the codes are gone!

tunde783:
thanks so much, i have fixed other codes, the only code left is the p0016 code, i am looking for an expert on this. thanks.

Don't you trust the same guy to fix the P0016?

olaboy1:
Yes I had the ignition on. I will try and find some pins or sewing needles to help me back probe the ECM connectors properly.
And I need to shop for one manufacturer's spec upstream A/F sensor for now as one of the upstream sensors is reading 12ohms. It was the exact sensor the old mechanic put because he said the old one in the CAT had worn threadings, so I guess he didn't bother to check, just went on to buy a sensor.
Could you point me to the right PDF showing the sensor part number specific for my car.

Yes, you need a pin or sewing needle to successfully back-probe

It is reading 12 ohms instead of .....

Checking....will update the space if and when found!

olaboy1:
I have done voltage test (ECM pins direct) for P1135/P1155 and both came out with 0.41v, and the manual says I should have 9-14v.

I think I have started putting 1+1 together. The ECM is under the pigeon hole, my current car had a heater blower problem and it was located at the same position under the pigeon hole, and you know the pigeon hole is a compartment people open a lot or maybe that part of the car is prone to road impact and this may have affected the ECM just like it affected my car's heater blower that I had to change myself.

ignition on?

back-probe?

if the ECM is sick, then it cannot command/control the oxygen sensors properly, let's hope it is not at fault!

olaboy1:
I don't know if I did the check correctly. I unplugged the connectors and just checked the pins inside the ECM directly using a DMM, or do I leave the connectors on and back probe from the wires on the connector.

back-probe is the correct way!

ignition must be on!!

DMM on Volts range!!!

olaboy1:
That's the pix for the ECM pins to check.

Yea, that's true!