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Nissan Micra K11 1.0 2002 - MIL on, weak mixture? (waveforms) - Fixed #

Posted by Malcolm Tripp on March 16, 2011, 9:07 pm

Year of Manufacture *: 2002
Engine Size and Code *: 1000
( Optional ) Scanner Used: Solus Pro / Picoscope

Mil light on code suggested weak mixture, checked for air leaks, non found, scoped both oxygen sensors and AMM waveforms attached.

Question is 1. Why so much noise on AMM pattern, leads kept away from all sources of interference.
2. The pre cat sensor appears to be switching
ok post cat sensor has high reading suggesting rich mixture and cat not doing very much.
3. Long and short term fuel trims hovering around 100 +/- 15% how much bearing will the post cat sensor have on the long term trim.

When code is cleared and adaptions reset the Mil light stays out for exactly 85 miles

!T

Any thoughts appreciated

Re: Nissan Micra K11

Posted by Pete Mutlow <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1569' width='330' height='300' border=0 style='border:none;'> on March 16, 2011, 9:31 pm, in reply to "Nissan Micra K11"
Peter Mutlow

Hi Malcolm,

So what was the fault code? Would be interested in 4 gas readings at both idle and fast idle. Had a problem with a Fault Code Po200 Micra with the light coming on at about the same mileage time as yours about a year or so ago. It is in the archives.

Regards

Pete M

Re: Nissan Micra K11

Posted by ukat3096 <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3096' width='330' height='300' border=0 style='border:none;'> on March 16, 2011, 10:30 pm, in reply to "Re: Nissan Micra K11"
Lee Woods

Take the car on the road and drive under a bit of load for a while watch what the pre cat lamda is doing, make sure its still switching and not going to the weak side.

A steady high reading from the post cat lamda say 0.7 volts or above is saying that the cat is efficient ..not so much rich Malcomn but low of oxygen (effects of good cat burning oxygen up)

If it was rich the pre cat lamda would report it, assuming that if fuel trims are good at base 0 they are reporting a weak trend.

I tend to take the scanner out on the road now in the vehicle and watch what lamdas are doing under load, sat in the workshop they can show good switching , under load can be a different story.

Try giving air flow meter hot wire a clean with brake cleaner.

Re: Nissan Micra K11

Posted by Andrew Kevans <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1724' width='330' height='300' border=0 style='border:none;'> on March 16, 2011, 10:38 pm, in reply to "Nissan Micra K11"
Andrew Kevans

Good question had an almera in today with near identical waveform had a PO335 code crank sensor signal. Looked at actual data with KTS and noticed AMM dropping out to 1.8v WOT 5th gear and pre cat sensor 0.1v faulty air mass meter? problem is I've seen this noise before on previous nissan almera tino and found signal wire broken where it joined the main loom repaired wiring and car ran OK although noise was still present but not quite as bad.Back to car today scoped crank and cam timing ok but chain badly stretched and car misfiring on acceleration more testing tomorrow

Re: Nissan Micra K11

Posted by Mark Robins <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1448' width='330' height='300' border=0 style='border:none;'> on March 17, 2011, 8:23 am, in reply to "Re: Nissan Micra K11"

May not be relevant but the ground on the O2 sensor gives problems on these so worth a check. Noise on scope images is usually interference from earthing to battery or vehicle, try a floating earth to O2 sensor and also try activating filter option in drop down menu (channel options). The use of the M1007 passive high impedance probe gives better results than the standard lead supplied. Pico supply the lead if you didn't get them in your kit.

Mark

Re: Nissan Micra K11

Posted by Malcolm Tripp <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5337' width='330' height='300' border=0 style='border:none;'> on March 17, 2011, 9:53 am, in reply to "Re: Nissan Micra K11"
Malcolm Tripp

Post cat signal, Pico example waveform shows it should be near zero volts, scoped an 08 ford Ka and it was found to be as waveform suggested.

Cannot remember the the exact code number but the description was "mixture lean"

Tried earthing on the sensor earth and it made no difference.

Interestingly the front sensor was switching between 0.3 and 1.2 volts with battery earth and dropped to 0.1 and 0.9 volts with sensor earths however both sensors generated a fault code for voltage low using their earths ???

Car back next week, will give it an on road check and report back.

Re: Nissan Micra K11

Posted by paul mccooke <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5379' width='330' height='300' border=0 style='border:none;'> on March 17, 2011, 10:58 pm, in reply to "Re: Nissan Micra K11"
Paul McCooke

Hi Malcolm, ive taken a look at the pico example i think you have been looking at, and at best it is misleading. UKAT3096's post already explained that a post cat o2 sensor signal voltage will be high with a good cat this is correct. Pull another car in and scope pre and post sensors again,you will need to rev the engine for a surprising amount of time for both sensors to get hot enough to output, and for the cat to flash and start operating, post sensor will go high and level because there will be very little oxygen left after the cat has reacted.
Fuel trim errors can be tricky to nail, because the root problem can be so many things, air leaks, as you have already mentioned, dont forget the crank breather system though, its part of the induction system, slight missfires(for numerous reasons), injector performance, fuel pressure and flow, do not overlook these physical things before you get lost in the 'lambda loop' hth keep scoping and posting.
Flat out air mass figure from live data might be helpful, and i have also seen interference on AMM signals like yours with no running problems.
Regards Paul

Re: Nissan Micra K11

Posted by Malcolm Tripp <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5337' width='330' height='300' border=0 style='border:none;'> on March 24, 2011, 8:32 pm, in reply to "Re: Nissan Micra K11"

Had car back yesterday, carried out road test as suggested attached are Solus Pro graphs car taken on a twenty mile run mixed and motor way driving.

Code p0171 retrieved from ecu and cleared

My impressions are that rear oxygen sensor broadly mirrors the first, I feel the cat is not doing very much, ltft is up to 125% but mil never came on.

If the cat is not working would the rear sensor affect ltft ?

Also carried out smoke check for air leaks nothing found !

Noticed water temp does not go over 65c replaced sensor but acts the same. suspect this would cause rich condition anyhow.

appreciate your comments

Re: Nissan Micra K11

Posted by lee woods <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3096' width='330' height='300' border=0 style='border:none;'> on March 24, 2011, 9:42 pm, in reply to "Re: Nissan Micra K11"
Lee Woods

The rear lamda like you say does look like its to active at the steady throttle areas , not sure about if the rear lamda sensor affects fueling trim.
The ltft seems excessive, have you tryed a clean on the air mass hot wire, maybe check fuel pressure and flow rate also, power down ecm and re road test see if trims come more inline.

Re: Nissan Micra K11

Posted by Malcolm Tripp <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5337' width='330' height='300' border=0 style='border:none;'> on March 25, 2011, 10:03 am, in reply to "Re: Nissan Micra K11"
Malcolm Tripp

Fuel pressure checked and found spot on, flow good 1ltr in 30 seconds so no problems there.

Ecu has been powered down several times to re set adaptions.

Air mass meter has been substituted with a known good one.

Thanks for your suggestions, vendetta goes on !

Re: Nissan Micra K11

Posted by Paul Mccooke <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5379' width='330' height='300' border=0 style='border:none;'> on March 29, 2011, 9:51 pm, in reply to "Re: Nissan Micra K11"

Hi Malcolm,might be worth pulling injectors on this and getting them bench checked.

Re: Nissan Micra K11

Posted by Lee morton <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3142' width='330' height='300' border=0 style='border:none;'> on April 6, 2011, 2:13 pm, in reply to "Re: Nissan Micra K11"
Lee Morton

hi malcolm did you get to the bottom of this problem i have the exact same thing on same car just wondering if you fixed it thanks lee

Re: Nissan Micra K11

Posted by Dave Hill <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2783' width='330' height='300' border=0 style='border:none;'> on April 7, 2011, 10:50 pm, in reply to "Re: Nissan Micra K11"

Hi Malcolm

It is worth scoping the Oxygen Sensor VS the Mass Air meter during a snap wide open throttle event & observing the relationships.

Just today I had an Almira dropped off from my local Vauxhall Dealership. I had scanned it last week & pulled a P0171 & advised them to check the MAF sensor. They took my words too literally & replaced it & the light came back on.

Like I said, it returned today & again it had P0171 stored. The O2 vs MAF sensor snap throttle waveform exposed an immediate problem. The O2 sensor volts took a shift far into the negative volts. However there was no evidence of a fault during the idle & fast checks.

You really need to study the signals whilst challenging the components!

Darren Cotton has recently posted (on ilexa) a real nice example of this type of waveform. If we are lucky, he might post it on UKAT too...

Re: Nissan Micra K11

Posted by John Ritchie <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2638' width='330' height='300' border=0 style='border:none;'> on April 7, 2011, 11:43 pm, in reply to "Re: Nissan Micra K11"

Sorry to change the subject slightly but Dave mentioned a post on ilexa referring to Maf vs O2 sensor on WOT .
I took a look and i see the peak voltage visually has a higher peak volts but the initial reaction time and overall sample is much the same to me.I see the idle pulse is slightly more enhanced but to a basic scope user like me ,i would like to know why the faulty maf didn't send the o2 rich or should i say why didn't it stop the o2 sensor switching ?.
For the small amount of votage/time variation is it a case you have to capture each specific model/engine to then have a accurate library of data to draw on ?

Your thoughts please
Regards
John

Re: Nissan Micra K11

Posted by Malcolm Tripp <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5337' width='330' height='300' border=0 style='border:none;'> on April 8, 2011, 8:19 pm, in reply to "Re: Nissan Micra K11"
Malcolm Tripp

Been waiting for this to come back, customer is a Padre in the RAF and commutes to Basingstoke.

Today by coincidence had another Micra in with no problems, customer quite happy for me to swap AMM for testing purposes, this AMM runs at 1.25v at idle the one on problem car runs at 1.55v ?

Given it back for him to use and we will see if it makes a difference, schools broke up today so may be a while until I can have it back.

I was quoted £500+ for complete throttle body this is why I am doubtful about condemning it with out being certain.

Fixed #

Posted by Malcolm Tripp on April 30, 2011, 6:59 pm, in reply to "Re: Nissan Micra K11"
Message modified by board administrator May 19, 2011, 2:58 pm

FIX !

Well we finally got there on this one.

I replaced the AMM with one from another car and it ran much better, scoped it up and the only difference I could see was at idle the base voltage is 1.50v on faulty AMM and 1.25v on trial unit, 500 miles over Easter later and no MIL on, fuel trims checked s/t 100% l/t 105% looked pretty good to me and we managed to source just the AMM and not the whole throttle body at over £500.

Consider this put to bed and thanks for all the responses.

Re: Fixed #

Posted by Jim Power <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3202' width='330' height='300' border=0 style='border:none;'> on July 13, 2013, 12:13 pm, in reply to "Fixed #"
James Power

Hi Malcolm

Old thread I know. But can you remember where you sourced the sensor for this, or anyone else for that matter. I'm having trouble pinning down a genuine Bosch one.

Main dealer €990 inc VAT for a complete throttle body for a 01 car.

Bosch part No 0 280 218 040

Tia, Jim.

jim power

Re: Fixed #

Posted by MALCOLM TRIPP <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5337' width='330' height='300' border=0 style='border:none;'> on July 16, 2013, 9:02 pm, in reply to "Re: Fixed #"
Malcolm Tripp

Hello

I bought a cheap Chinese one on E Bay as I thiught it worth a punt, It was not !!!!

Allparts (Hayes) supplied the one finally fitted.

Re: Fixed #

Posted by Jim Power <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3202' width='330' height='300' border=0 style='border:none;'> on July 17, 2013, 10:27 pm, in reply to "Re: Fixed #"
James Power

Thanks Malcolm

Thanks for your reply.

I thought you may have sourced a Bosch one but it seems not to be available outside of the Nissan dealer.

Regards Jim.

jim power

Re: Fixed #

Posted by Tony Sefton <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5581' width='330' height='300' border=0 style='border:none;'> on July 18, 2013, 8:39 am, in reply to "Re: Fixed #"
Tony Sefton

When Manufacturers come up with Extortionate prices like these and refuse to sell a small part that you require, look at other models in the range. On this occasion, Just think Almera and you can buy an AFM for as little as £27.00 + vat Exchange from Bosch. ( might be a little more with price increases etc )

You will have to swap the Air temperature sensor over as the Almera doesn't have one but the terminals are there to solder to.

We have sold 100,s or may now be into 1000,s of air flow sensors and I always buy the cheapest version as long as it has the correct fitting, I know Bosch state that the sensors are metered to the pipe size etc and should not be swapped but I have not had 1 single complaint of warning lights coming on, lacking power or MOT emissions failure, Which If there was a considerable difference in these sensors then I am sure that we would have some complaints.

I have also seen and tried several versions of Aftermarket sensors and never yet seen one that works properly.

Re: Fixed #

Posted by Jim Power <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3202' width='330' height='300' border=0 style='border:none;'> on July 19, 2013, 6:00 pm, in reply to "Re: Fixed #"
James Power

Thanks Tony

I wont be fitting an aftermarket sensor, it's not a hole I intend digging for myself.

I like your suggestion though, would be described as "thinking outside of the box"

Jim.

jim power

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