olaboy1:
To break it down clearly.
1. ECM check is for voltage
2. Oxygen sensor check is for resistance, continuity, short and voltage (The voltage test is well done when the sensor is heated to 600-1200 degrees Fahrenheit and best tool for this is an OBD2 scanner as that would also show us the frequency movement we should expect in a FSM specified voltage range)
3. Wire harness check is for resistance, continuity, short and voltage. (The voltage test will be when the wire harness is connected to the ECM and ignition switch ON and a DMM comes in handy to do just that job)
4. E.F.I relay is to check continuity between its relay block and the heater terminal of the oxygen sensor

Can you direct me to the fuses/relays positions in the fuse box controlling all the 4 oxygen sensors voltage circuit in the ECM. If I am correct each sensor has it's own connector pins on the ECM and of course should have dedicated fuse/relay e.g ECM E10 and E9 connectors for the downstream sensors giving DTC's P0161/P0141.

I want to start from fuses and relays because that's where I first look as a novice anytime I have a problem with my car.

My FSM is asking me to check for resistance only in the oxygen sensor. Please how do I check for continuity and short, I don't need to check for voltage anyway if I don't have continuity or if I have a short, I will just go ahead and change the sensor.

The PDF file m_05_0057 for the downstream sensors (P0161/P0141) is very clear, but the PDF file m_05_0098 for the upstream sensors(P1135/P1155) did not explain the rapair procedure like it did for the former. Where do I look to get same repair info contained in m_05_0057.

I appreciate your time and effort.

Your continuity test for the O2 sensors was wrong.
You ought to connect the multimeter probes to the positive and negative pins on a sensor not to one pin on a sensor and ground of the car; it's impossible to have continuity between the sensor and car when sensor is disconnected. I hope this helps.

AutoElectNG:
Let's troubleshoot

DTC P1135, P1155, P0141 AND P0161 in that order

For P1135 and P1155, see m_05_0098

For P0141, see
m_05_0332
m_05_0277
m_05_0029
m_05_0092
m_05_0007
m_05_0018
m_05_0057

For P0161, see
m_05_0007
m_05_0018
m_05_0057

If you are done going through all of that, then we can begin taking a closer look at what might be wrong with your ride

Somehow we forgot to follow this order, so let's follow this order.

That is P1135, P1155, then P0161

timifakay:


Your continuity test for the O2 sensors was wrong.
You ought to connect the multimeter probes to the positive and negative pins on a sensor not to one pin on a sensor and ground of the car; it's impossible to have continuity between the sensor and car when sensor is disconnected. I hope this helps.

Thanks I have done it correctly now between the two heater circuit black wires in the oxygen sensor and I have continuity in all the sensors...they all beeped.

AutoElectNG:


Somehow we forgot to follow this order, so let's follow this order.

That is P1135, P1155, then P0161

I agree we work in that order, from up to down. But I can't find the fix steps in the PDF for fixing P1135/P1155 (m_05_0098)

I have access to my ECM now and I have done the voltage test for P0161/P0141 and no voltage when I used my DMM to check the right pins shown in the diagram. I enlarged the PDF to see the pins properly. My ECM is exactly as shown in the pix with the same numbers of pins and positions. There are 5 connectors on my ECM. But when I go into the engine bay to check the wire harness coming from my ECM, I have 11.9v each for P0161 and P1135.

I can't make any conclusion yet on what's going on at the ECM end until I do a voltage check for P1135/P1155 on the ECM pins.
How do we proceed, because it doesn't look like the problem is coming from the sensors.

I have used my DMM to check all the fuses in the fuse box and they all have continuity, even the 7.5A fuse for the OBD self diagnosis system has continuity.

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

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.

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.

Briefly available, let's try to answer your posts in the order in which they were posted

olaboy1:


Remember we said all 4 sensors are priority 1 because FSM wrote that address all DTC's that are not fuel trim and misfire DTC's. Since am in the engine bay already I just thought I should take all the required readings at once.

If you insist we address the upstream A/F sensors first then I have no problem with that

Final position?

AutoElectNG:


Final position?

Yes final position.

olaboy1:
Talking about starting from fuses and relays first, I am looking at the instruction book from the car and I see the table of the fuse box and on number 12: OBD 7.5 A: self diagnosis system.
Remember the report said no self test carried out.
So in this case wouldn't it be more logical to start from the 7.5A fuse than to go start checking the OBD2 interface.
What do you think

Which PDF and which page of that PDF are you referring to?

I think the logical place to start is where the manufacturer suggests unless we have cogent reasons not to!

sorry I wasn't referring to the FSM, it was the instruction booklet in the car and I've attached a page on that here.

Yes I am following the FSM, and I've checked the voltage at the ECM.

olaboy1:
To break it down clearly.
1. ECM check is for voltage

2. Oxygen sensor check is for resistance, continuity, short and voltage (The voltage test is well done when the sensor is heated to 600-1200 degrees Fahrenheit and best tool for this is an OBD2 scanner as that would also show us the frequency movement we should expect in a FSM specified voltage range)

3. Wire harness check is for resistance, continuity, short and voltage. (The voltage test will be when the wire harness is connected to the ECM and ignition switch ON and a DMM comes in handy to do just that job)

4. E.F.I relay is to check continuity between its relay block and the heater terminal of the oxygen sensor

The first check is a voltage check on the ECM, can it command/control the oxygen sensors? That is why the ignition is turned on!

The second check is not a voltage check but a resistance check. The voltage test of which you speak is not done by the OBD Scan Tool but the ECM, the OBD II Scan tool merely reports the results to you. Ignition is not on! So voltage which is like water cannot flow! In fact, the FSM is incomplete. It presumes that you already know that the battery must be disconnected. Because it is wrong to check for resistance with a powered circuit!

The third check is not a voltage check but a resistance check. Ignition is not on! So voltage which is like water cannot flow! In fact, the FSM is incomplete. It presumes that you already know that the battery must be disconnected. Because it is wrong to check for resistance with a powered circuit!


The forth check is not a voltage check but a resistance check. Ignition is not on! So voltage which is like water cannot flow! In fact, the FSM is incomplete. It presumes that you already know that the battery must be disconnected. Because it is wrong to check for resistance with a powered circuit!

Can you direct me to the fuses/relays positions in the fuse box controlling all the 4 oxygen sensors voltage circuit in the ECM. If I am correct each sensor has it's own connector pins on the ECM and of course should have dedicated fuse/relay e.g ECM E10 and E9 connectors for the downstream sensors giving DTC's P0161/P0141.

I want to start from fuses and relays because that's where I first look as a novice anytime I have a problem with my car.

Yes, each sensor has its pins on the ECM but I am not sure each sensor has its own fuse/relay

Have to check the wiring diagram to provide an answer, will check in the evening

My FSM is asking me to check for resistance only in the oxygen sensor. Please how do I check for continuity and short, I don't need to check for voltage anyway if I don't have continuity or if I have a short, I will just go ahead and change the sensor.

https://www.youtube.com/watch?v=x3nqlXM6nOM


https://www.youtube.com/watch?v=euz9ENGFKZs

The PDF file m_05_0057 for the downstream sensors (P0161/P0141) is very clear, but the PDF file m_05_0098 for the upstream sensors(P1135/P1155) did not explain the rapair procedure like it did for the former. Where do I look to get same repair info contained in m_05_0057.

Will provide a breakdown when we take a look at the manual in a couple of hours
I appreciate your time and effort.

[/quote]

timifakay:


Your continuity test for the O2 sensors was wrong.
You ought to connect the multimeter probes to the positive and negative pins on a sensor not to one pin on a sensor and ground of the car; it's impossible to have continuity between the sensor and car when sensor is disconnected. I hope this helps.

Thanks brother!

olaboy1:


Thanks I have done it correctly now between the two heater circuit black wires in the oxygen sensor and I have continuity in all the sensors...they all beeped.

Progress!

You understand continuity now!

olaboy1:


I agree we work in that order, from up to down. But I can't find the fix steps in the PDF for fixing P1135/P1155 (m_05_0098)

I have access to my ECM now and I have done the voltage test for P0161/P0141 and no voltage when I used my DMM to check the right pins shown in the diagram. I enlarged the PDF to see the pins properly. My ECM is exactly as shown in the pix with the same numbers of pins and positions. There are 5 connectors on my ECM. But when I go into the engine bay to check the wire harness coming from my ECM, I have 11.9v each for P0161 and P1135.

I can't make any conclusion yet on what's going on at the ECM end until I do a voltage check for P1135/P1155 on the ECM pins.
How do we proceed, because it doesn't look like the problem is coming from the sensors.

I have used my DMM to check all the fuses in the fuse box and they all have continuity, even the 7.5A fuse for the OBD self diagnosis system has continuity.

no voltage when I used my DMM to check the right pins shown in the diagram.

ignition on or not?

But when I go into the engine bay to check the wire harness coming from my ECM, I have 11.9v each for P0161 and P1135.

How did you do this test?

How do we proceed, because it doesn't look like the problem is coming from the sensors.
ignition on

back-probe

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

Yea, that's true!

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:
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!

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.

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!

AutoElectNG:


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!

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.

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?

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.

Congrats Tunde. You had like 12 DTC's, can you give a brief breakdown how you got 11 DTC's fixed.

olaboy1:


Congrats Tunde. You had like 12 DTC's, can you give a brief breakdown how you got 11 DTC's fixed.

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.

AutoElectNG:


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

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

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:


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

belt or chain?

AutoElectNG:


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

"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.

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

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

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