MOT and the EML?

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eltax91

Original Poster:

9,842 posts

205 months

Tuesday 13th January 2015
quotequote all
Hi guys

My mother in law has an old Almera that's had the engine management light on for some time. Fault codes show up as O2 sensor fault. At the last mot her friendly old mechanic changed all the sensors, which didn't solve the problem so he diagnosed it as being somewhere in the wiring. He advised she not spend the money on tracing the fault as the car is not worth it. He also suggested that the light went out when he actually started the car, so he could pass it this year ( wink ) but she was not to return next year for the mot!

As it happens the car runs perfectly sweet but it's now due it's mot again and no friendly mot guy anymore. I'm going to run it through for her to see if there are any other failure points and then decide what to do thereafter.

Anyway, given she has run around with the light on for a year, it's a pretty much useless light now as it won't tell her if any other issues as its permanently illuminated by this seemingly unfixable wiring fault.

Does she have any options here? Would it be difficult to wire it to another light in the cluster than behaves the same in the start up procedure?

Or could the offending sensor wiring be butchered to send back and 'all clear' signal to the ecu? Therefore losing only the reading from that sensor.

Seems a shame to move on a solid car for such a small issue.

Another question. When I clear the code with my Bluetooth reader/ android tablet, it stays off for a good few minutes. At what point would the tester normally check the lights?

Could I clear it before handing the keys over and sit in the viewing bay and keep trying to clear the code and maybe get away with it I wonder?!

t400ble

1,804 posts

120 months

Tuesday 13th January 2015
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Eml isnt a failure for mot test

morgrp

4,128 posts

197 months

Tuesday 13th January 2015
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They leave them running to get them hot for the emissions testing anyway so the light would no doubt come back on - This could of changed? but I think provided emissions are within test parameters the EML light is not a fail, ABS, Traction control EBD and SRS lights are though

Jimmyarm

1,962 posts

177 months

Tuesday 13th January 2015
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t400ble said:
Eml isnt a failure for mot test
This, remains an advisory only.

aw51 121565

4,771 posts

232 months

Tuesday 13th January 2015
quotequote all
Put it in for the MoT and see what happens. It won't be a wiring fault wink , I suggest a Nissan specialist - or a Nissan forum - will be able to explain the issue and offer solutions (if the last MoT tester was suggesting a wiring fault after "changing all the sensors" then I'd suggest he/she isn't worth their salt).

As a starter for ten, modern/recent vehicles have TWO O2 sensors - one upstream of the catalytic converter and the other downstream. A mismatch between expected values from the two sensors (such as a cat failure) will flag a fault and light up the light - but my spidey sense suggests the downstream O2 sensor has gone nuts as the Almera passed the emissions test last MoT.

Full diagnostics will point to the fault smile ; trying a new MoT tester sounds like a plan cloud9 !!

McSam

6,753 posts

174 months

Tuesday 13th January 2015
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There's no need to guess when the complete MOT testers' manual is freely available:

https://www.gov.uk/become-an-mot-station/mot-testi...

No mention of EML anywhere in it. The only warning lamps I can see included are airbag/seatbelt systems, brakes, ESC and TPMS if fitted.

eltax91

Original Poster:

9,842 posts

205 months

Tuesday 13th January 2015
quotequote all
aw51 121565 said:
Put it in for the MoT and see what happens. It won't be a wiring fault wink , I suggest a Nissan specialist - or a Nissan forum - will be able to explain the issue and offer solutions (if the last MoT tester was suggesting a wiring fault after "changing all the sensors" then I'd suggest he/she isn't worth their salt).

As a starter for ten, modern/recent vehicles have TWO O2 sensors - one upstream of the catalytic converter and the other downstream. A mismatch between expected values from the two sensors (such as a cat failure) will flag a fault and light up the light - but my spidey sense suggests the downstream O2 sensor has gone nuts as the Almera passed the emissions test last MoT.

Full diagnostics will point to the fault smile ; trying a new MoT tester sounds like a plan cloud9 !!
Thanks for the reply. This new fault developed after a long and expensive offering fault that also trough the eml. Turns out the only Renault part on the car (timing chain) had stretched!

A different garage had only months before changed the timing chain and crank/ cam sensors.

The new mot man was clearly pulling porkies about the warning light, making out he had done her a favour. But She does have an invoice for two O2 sensors. Whether they were changed or not is another matter. smile

daveofedinburgh

556 posts

118 months

Tuesday 13th January 2015
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t400ble said:
Eml isnt a failure for mot test
^This.

As a PHer who has moved around the UK a bit, and therefore had MOT tests in countless different stations, there is a real lack of consistency.

EML light should be an advisory. I had a station fail a friends' car (which I took to the station for them) for an EML light. They were quick to issue a pass when I pointed out it wasn't a fail.

I also presented my own car with an EML light at another station (forget what the fault was now!) which didnt even get an advisory.

Once had an E36 saloon with an airbag light that the previous owner had popped an Apple sticker over, which passed no problem.

Presented another car with an airbag light for MOT, which they rightly failed. Were happy to pass when re-presented with the car afew days later, whose airbag light miraculously didnt light up at all... no idea how that happened. :-0 Worth pointing out that this was a long time ago, and that I value the safety of my passengers (and myself!) enough to make sure the airbags work now.

In my experience, 'council' MOT stations are the ones to go to, as they play by the rules and won't try to rinse you. If you have something (not a safety item ofcourse!) which you know is a fail, non-council stations will be more likely to bodge it through if you 'negotiate'. Worst case scenario, try the MOT station down the road.

For all this cavalier talk, I genuinely dislike the inconsistency in UK MOT testing. Im old and responsible enough now to just fix my cars' faults, even the sheds. Something like an EML light can normally be sorted/ reset without too much difficulty, and the warning light is there for a reason.

There's a station in north London which is known to pass just about anything for £75. The type of place you take your de-catted Impreza and they stick the probe in another cars' exhaust to get it through. Have to wonder how many bald-tyred, knackered-brakes sh*tters are rolling around incapable of an emergency stop due to these unscrupulous cowboys?


Toaster Pilot

14,615 posts

157 months

Tuesday 13th January 2015
quotequote all
If it's an O2 sensor related issue it could fail on emissions of course despite the EML not being a fail...

eltax91

Original Poster:

9,842 posts

205 months

Tuesday 13th January 2015
quotequote all
Toaster Pilot said:
If it's an O2 sensor related issue it could fail on emissions of course despite the EML not being a fail...
Yep. It's a council station I take it to so I will get an 'honest' test. I will give it death all the way there and see if I can't lower those emissions. smile

Limpet

6,293 posts

160 months

Tuesday 13th January 2015
quotequote all
daveofedinburgh said:
Presented another car with an airbag light for MOT, which they rightly failed. Were happy to pass when re-presented with the car afew days later, whose airbag light miraculously didnt light up at all... no idea how that happened. :-0 Worth pointing out that this was a long time ago, and that I value the safety of my passengers (and myself!) enough to make sure the airbags work now.
Seems like a very inconsistent approach from the testing station. If they failed it for the light being on, they should also have failed it on the retest for the light not illuminating.

I am about to submit a car for a test with the interior stripped out of it. That will be a first for me smile

Spangles

1,441 posts

184 months

Tuesday 13th January 2015
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Limpet said:
daveofedinburgh said:
Presented another car with an airbag light for MOT, which they rightly failed. Were happy to pass when re-presented with the car afew days later, whose airbag light miraculously didnt light up at all... no idea how that happened. :-0 Worth pointing out that this was a long time ago, and that I value the safety of my passengers (and myself!) enough to make sure the airbags work now.
Seems like a very inconsistent approach from the testing station. If they failed it for the light being on, they should also have failed it on the retest for the light not illuminating.

I am about to submit a car for a test with the interior stripped out of it. That will be a first for me smile
Airbag light is only a fail if it's on, pass and advise if it doesn't come on at all.

Claudia Skies

1,098 posts

115 months

Tuesday 13th January 2015
quotequote all
eltax91 said:
Yep. It's a council station I take it to so I will get an 'honest' test. I will give it death all the way there and see if I can't lower those emissions. smile
Why not talk to the Nissan dealer? You're far more likely to get help than under the railway arches or from the council. As someone else has said; step 1 is proper diagnosis.

eltax91

Original Poster:

9,842 posts

205 months

Tuesday 13th January 2015
quotequote all
Claudia Skies said:
Why not talk to the Nissan dealer? You're far more likely to get help than under the railway arches or from the council. As someone else has said; step 1 is proper diagnosis.
It's an 11 year old worthless nissan. Step one is to see if it passes. If it does, there is no step 2, other than drive it! smile

Toaster Pilot

14,615 posts

157 months

Tuesday 13th January 2015
quotequote all
eltax91 said:
It's an 11 year old worthless nissan. Step one is to see if it passes. If it does, there is no step 2, other than drive it! smile
Don't need to pay for dealer diagnostics either, just find someone with decent kit that knows how to properly diagnose a fault not just put parts on according to the code.

imagineifyeswill

1,224 posts

165 months

Tuesday 13th January 2015
quotequote all
EML light isnt an MOT fail, the light on quite possibly is a wiring fault there is a well known fault with the wiring loom round the steering column on Almera,s requires a part loom replacement by Nissan, expensive I would just ignore it.

mcford

819 posts

173 months

Tuesday 13th January 2015
quotequote all
Limpet said:
Seems like a very inconsistent approach from the testing station. If they failed it for the light being on, they should also have failed it on the retest for the light not illuminating.

I am about to submit a car for a test with the interior stripped out of it. That will be a first for me smile
It may seem inconsistent but it is by the book and the way that it should be done.

Hopefully your tester will have a bit of common sense with regard to that the seats dictate the seat belt requirements. A grey area that I forsee is if any SRS components were originally fitted to the now removed seats as that's technically a fail.

With regard to the EML, I tested a Seat the other week with the EML on and I have never seen such a near perfect emissions test result CO 0% on fast idle and idle, HC 0ppm and lambda at 0.999.

eltax91

Original Poster:

9,842 posts

205 months

Tuesday 13th January 2015
quotequote all
imagineifyeswill said:
EML light isnt an MOT fail, the light on quite possibly is a wiring fault there is a well known fault with the wiring loom round the steering column on Almera,s requires a part loom replacement by Nissan, expensive I would just ignore it.
Interesting. Any more info on the fault please?

Limpet

6,293 posts

160 months

Tuesday 13th January 2015
quotequote all
Spangles said:
Airbag light is only a fail if it's on, pass and advise if it doesn't come on at all.
I stand corrected. I thought it was the same test criteria as the ABS light.

Mind you, it seems a bit daft to have a warning light in the test that you can just pull the bulb out of to get a pass.

Claudia Skies

1,098 posts

115 months

Tuesday 13th January 2015
quotequote all
Limpet said:
Mind you, it seems a bit daft to have a warning light in the test that you can just pull the bulb out of to get a pass.
I'm not sure that's right. These days the tester is supposed to check to make sure all the warning lights illuminate in the right sequence/for the right length of time.