mayor2013:


Is this Honda Accord 2009 the European spec or North American spec?

North America version

We

autologic:

North America version

Sounds strange though. I know the European spec ecu readiness is nothing to write home about. Am still following you on this sir

Data Collection
We make use of our trusted tool autel maxisys to retrieve the needed data for proper analysis of the issue:
Data for analysis:
1.DTC code:None !
2.scan data live data is depicted below
The first image shows scan data at idle condition

1st pix shows scan data at acceleration
2nd pix shows scan data at deceleration

(Analysing and comparing all our scandata we should able fish out the culprit responsible for the black smoke easily)

autologic:
2nd pix shows scan data at varying speed

Did you see the pulse rate of the injectors. 4.1m/s that's doubled of what d normal pulse rate

mayor2013:


Did you see the pulse rate of the injectors. 4.1m/s that's doubled of what d normal pulse rate

Spot on! that is part of pid indicating the high fuel consumption .
Also take note of the flaw air fuel ratio value

Evaluation stage(stop and think)
From the scan data ,we can easily infer that the fuel mixture is seriously running lean thus prompting the PCM to be adding fuel causing the overflogging of the mixture with fuel !
Then from the AFS reading we can easily see that the AFS pid value is stuck lean regardless of engine speed !
So further test is need to confirm the reason for the AFS value to be stuck lean ,maybe it is reacting to something or it is bad
So we continue from there subsequently !

autologic:

Spot on! that is part of pid indicating the high fuel consumption .
Also take note of the flaw air fuel ratio value

I saw that as well

Evaluation stage(stop and think)
Happy new month to everyone!
From where stop ,we have been able to prove that Honda air fuel ratio is stuck lean but we need to prove further if it is a case of stuck lean mixture or stuck lean signal .
Let look at the possibilities for such occurrence
1.AFS shorted to ground
2.Vacuum leak
3.Faulty AFS
4.Bad PCM

Evaluation stage(stop and think)
Based on our scan data result ,we can easily eliminate issue of vacuum leak
So we are left with this 3 factor which means that it is a typical case of stuck lean air fuel signal
1.Shorted AFS
2.Bad AFS
3.Bad PCM

Evaluation stage(stop and think)
Since we have been able to infer that it is due to a bad input signal issue ,we should go to through the route of low level electrical testing of signal to confirm all our available signal

Before go ahead with the test we need to be harmed with expected low level data and the electrical diagram of what we want to test ,
Below is the electrical wiring diagram of the AFS connection to the PCM

Our area of focus is the area circled

Pcm input to the AfS= (AFS+)
PCM low reference to AFS=(AFS-)

From Honda manufactured data
At idle AFS(+)=2.2V
At idle AFS(-)=1.8v

autologic:
Case 3

Car model :Honda accord 2009

Customer complaint: Exhaust is emitting black smoke with confirmed high fuel consumption


Scope of Job Resolution :Fix for the black smoke and resolution of high fuel consumption

N.B:what makes this case a peculiar one is that there is no DTC code registered on the PCM management system !

Bros please confirm engine type, from your scandata i suspect it is 2.4L i4, if i am correct, then is it K24Z2 or K24Z3..Some of us dey learn work for cartalk

thebigkendo:


Bros please confirm engine type, from your scandata i suspect it is 2.4L i4, if i am correct, then is it K24Z2 or K24Z3..Some of us dey learn work for cartalk

Sorry for not including those data I will make the appropriate correction .
Engine capacity -2.4L I4 ,k24Z2

autologic:
From Honda manufactured data
At idle AFS(+)=2.2V
At idle AFS(-)=1.8v

Kindly note that this value are PCM input reference value to AFS that is valid for almost all late model of Honda.

At this point I will need to reiterate that knowledge of basic skill of electrical concept and troubleshooting skill cannot be separated from automotive diagnosis cos what actually runs at the background on your scan data is basic electrical signaling !
Anybody that run diagnoses and cannot go low level electrical troubleshooting for further test is still a trial and error technician !
What we can even test on the low level is analogue signal but.
what really control the electrical signaling is programming algorithms from the PCM hence for the reason for the PCM naming (powertrain contro Module ).aka engine computer (street name brainbox )
The main purpose of the scan data to isolate the possible area of fault out of the whole array of complex system ,in other words the main diagnoses is the analysis of data and electrical testing !
The more quantity and quality of data that can be retrieved will go along way in achieving accurate fix

autologic:
Case 3

Car model :Honda accord 2009
Engine : K24Z2 2.4L i4
Customer complaint: Exhaust is emitting black smoke with confirmed high fuel consumption


Scope of Job Resolution :Fix for the black smoke and resolution of high fuel consumption

N.B:what makes this case a peculiar one is that there is no DTC code registered on the PCM management system !

Corrected

autologic:

Sorry for not including those data I will make the appropriate correction .
Engine capacity -2.4L I4 ,k24Z2

thebigkendo:


Corrected

Thanks

Back to the case study !
The importance of conducting integrity test of the two PCM input data to the AFS will be the best accurate test for checking for :
1 .Bad PCM
2.Shorted AFS
3.Bad PCM

Test (Measure and compare)
The equipment that will be used for this purpose is
Autel Powerscan ps100 Electrical Diagnosis tool
your normal 1k multimeter can suffice for this test.
(No mind I am just an autel freak ! )

honmusa:

Hahaha... Following..

mayor2013:


Did you see the pulse rate of the injectors. 4.1m/s that's doubled of what d normal pulse rate

pls can you guys explain more on this.thanks

empron:
pls can you guys explain more on this.thanks

The injector pulse rate is the indicator of the rate that the ecu is commanding the injector to be supplying fuel .
For Honda generally ,under normal condition this shouldnt be more than 3 ms(if no accessories is on) but 4.1 ms is an outrageous value and a pointer to the fact that the car is consuming fuel at alarming rate due to flaw input signal thereby causing the black smoke symptoms.
Later I will provide the new scan data after resolution so that you can compare .

autologic:
Test (Measure and compare)
The equipment that will be used for this purpose is
Autel Powerscan ps100 Electrical Diagnosis tool
your normal 1k multimeter can suffice for this test.
(No mind I am just an autel freak ! )

Bros we are still waiting for results

thebigkendo:


Bros we are still waiting for results

Sorry bro,schedule is very tight cos of heavy workloads, I will definitely conclude this case as soon aas I am less busy.

thebigkendo:


Bros we are still waiting for results

For robust results?

timifakay:

For robust results?

autologic:
Evaluation stage(stop and think)
Based on our scan data result ,we can easily eliminate issue of vacuum leak
So we are left with this 3 factor which means that it is a typical case of stuck lean air fuel signal
1.Shorted A/FS
2.Bad A/FS
3.Bad PCM

So i am waiting for the result, even though i can guess which it most probably will be