MOT - engine management light - does it have to be visible?

MOT - engine management light - does it have to be visible?

Author
Discussion

thetapeworm

Original Poster:

11,190 posts

238 months

Wednesday 26th December 2018
quotequote all
I'm trying to troubleshoot a current problem, 4 sensors replaced so far, each one clearing a specific code apart from one lambda sensor. I've tried two now and the light still comes on. In the meantime the MOT has run out but I could do with be able to use the car.

If you take a vehicle for an MOT and the tester is unable to see an engine management light that's lit, say it's obscured by a sticker or similar, is that an issue apart from being totally council and shameful?

Just trying to think of a temporary work around until I get it sorted.

Athlon

4,998 posts

205 months

Wednesday 26th December 2018
quotequote all
Engine malfunction indicator lamp
Turn on the ignition and check that the engine malfunction indicator lamp (MIL) illuminates and then goes off. On some vehicles it will be necessary to start the engine before the MIL goes off.

You need to inspect MIL fitted to diesel vehicles with 4 or more wheels and first used on or after 1 July 2008.

Engine MIL inoperative or indicating a malfunction; Major

paintman

7,669 posts

189 months

Wednesday 26th December 2018
quotequote all
https://www.mot-testing.service.gov.uk/documents/m...

Scroll down & you'll find it covers both spark & compression ignition vehicles and relevant dates.
If it requires one & it either doesn't illuminate or indicates a fault it's Major & a fail so covering it up won't work.

thetapeworm

Original Poster:

11,190 posts

238 months

Wednesday 26th December 2018
quotequote all
Cheers, I thought they'd have this covered but thought I'd ask, best dust off my push bike!

zixujo

17 posts

63 months

Wednesday 26th December 2018
quotequote all
Remove the bulb or cover it with tape or whatever. Deal with it if it fails.

steve-5snwi

8,592 posts

92 months

Wednesday 26th December 2018
quotequote all
zixujo said:
Remove the bulb or cover it with tape or whatever. Deal with it if it fails.
Its when not if, the bulb needs to come on and go off.

Whats the fault codes you have & make and model ?

zixujo

17 posts

63 months

Wednesday 26th December 2018
quotequote all
IF. Sounds like you take your cars to the wrong people. My tester would pass it regardless.

thetapeworm

Original Poster:

11,190 posts

238 months

Wednesday 26th December 2018
quotequote all
He bulb can't be taken out, it's on the circuit board buried inside the sealed dial unit. Of course it could be broken down and damaged but I'm not doing that.

steve-5snwi said:
Whats the fault codes you have & make and model ?
It's an '02 petrol CRV...



I've replaced both lambda sensors, number 1 twice, and also the knock sensor as that was throwing a code too.

Codes only came up once I decided to sell it 😂

SS2.

14,455 posts

237 months

Wednesday 26th December 2018
quotequote all
The fault log is reporting higher than expected voltage from the heated O2 sensor.

It might be worth clearing the fault codes and disconnecting the affected sensor. If the fault remains high voltage, the problem is between the sensor plug and the ECU. If the fault changes tor low voltage, the problem is most likely to be the sensor itself.

steve-5snwi

8,592 posts

92 months

Wednesday 26th December 2018
quotequote all
If you clear the codes and the light goes off how long does the light stay off for ? if its 10 miles or so book the car in for an MOT, clear it in the carpark and prey it doesn't come on while being tested.

If you disconnect the sensor does the code change ?

Muddle238

3,871 posts

112 months

Wednesday 26th December 2018
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Ridiculous MOT rules, an EML covers a range of potential issues, often caused by a faulty sensor. How a faulty sensor translates into a major fault, which should deem it unroadworthy I do not know. I'm convinced it's all political tactics to get older vehicles off the road and more people into brand new cars for whatever reason.

Graunching_dave

85 posts

74 months

Wednesday 26th December 2018
quotequote all
zixujo said:
IF. Sounds like you take your cars to the wrong people. My tester would pass it regardless.
Sounds like your tester is a . I don’t want you or your potentially faulty vehicle driving anywhere near me.

anonymous-user

53 months

Wednesday 26th December 2018
quotequote all
Graunching_dave said:
zixujo said:
IF. Sounds like you take your cars to the wrong people. My tester would pass it regardless.
Sounds like your tester is a . I don’t want you or your potentially faulty vehicle driving anywhere near me.
rofl

over-reacting much?

Warby80

330 posts

91 months

Wednesday 26th December 2018
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JimSuperSix said:
Graunching_dave said:
zixujo said:
IF. Sounds like you take your cars to the wrong people. My tester would pass it regardless.
Sounds like your tester is a . I don’t want you or your potentially faulty vehicle driving anywhere near me.
rofl

over-reacting much?
Erm no, he is correct. Instead of encouraging people to find ways round the Mot, lets encourage people to keep their cars roadworthy…

OP, looks to me like you need to be looking at the wiring associated with the pre cat o2 sensor…

cat with a hat

1,484 posts

117 months

Wednesday 26th December 2018
quotequote all
Warby80 said:
JimSuperSix said:
Graunching_dave said:
zixujo said:
IF. Sounds like you take your cars to the wrong people. My tester would pass it regardless.
Sounds like your tester is a . I don’t want you or your potentially faulty vehicle driving anywhere near me.
rofl

over-reacting much?
Erm no, he is correct. Instead of encouraging people to find ways round the Mot, lets encourage people to keep their cars roadworthy…

OP, looks to me like you need to be looking at the wiring associated with the pre cat o2 sensor…
Another vote for over reacting.

Warby80

330 posts

91 months

Wednesday 26th December 2018
quotequote all
cat with a hat said:
Warby80 said:
JimSuperSix said:
Graunching_dave said:
zixujo said:
IF. Sounds like you take your cars to the wrong people. My tester would pass it regardless.
Sounds like your tester is a . I don’t want you or your potentially faulty vehicle driving anywhere near me.
rofl

over-reacting much?
Erm no, he is correct. Instead of encouraging people to find ways round the Mot, lets encourage people to keep their cars roadworthy…

OP, looks to me like you need to be looking at the wiring associated with the pre cat o2 sensor…
Another vote for over reacting.
Well look at it this way, the Mot is a basic minimum standard for a vehicle to be roadworthy...

oceanview

1,511 posts

130 months

Wednesday 26th December 2018
quotequote all
thetapeworm said:
He bulb can't be taken out, it's on the circuit board buried inside the sealed dial unit. Of course it could be broken down and damaged but I'm not doing that.

steve-5snwi said:
Whats the fault codes you have & make and model ?
It's an '02 petrol CRV...



I've replaced both lambda sensors, number 1 twice, and also the knock sensor as that was throwing a code too.

Codes only came up once I decided to sell it ??
If its an 2002 petrol then the light being on doesn't matter (for MOT) on your car- for petrol cars from 01 july 2003 and diesel 01 july 2008 only.

Rick2018

4 posts

63 months

Wednesday 26th December 2018
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Is any of the wiring damaged ? Did you replace with a direct replacement oem or a universal item

Patrick Bateman

12,143 posts

173 months

Wednesday 26th December 2018
quotequote all
Warby80 said:
Well look at it this way, the Mot is a basic minimum standard for a vehicle to be roadworthy...
The new rules mean the brake pad warning light being on is a fail despite the fact this could mean there's still twice the legal limit of pad material left.

So let's not pretend some of it isn't absolute bks.

Athlon

4,998 posts

205 months

Wednesday 26th December 2018
quotequote all
Patrick Bateman said:
The new rules mean the brake pad warning light being on is a fail despite the fact this could mean there's still twice the legal limit of pad material left.

So let's not pretend some of it isn't absolute bks.
Wrong, sorry.

1.1.13 Brake linings and pads
Some brake pads have metal wear indicators so that when the pads become excessively worn the metal indicator touches the disc making a squealing sound. Other pads may have a cut, which if worn away indicates that the pad must be replaced.

No mention of lights that I can see.

As for the over reaction comment, I don't agree that it is, if you are prepared to overlook that which is an absolute fail then what else? fudge the emissions test, that's easy to do, overlook corrosion or broken springs? also easy.

You either test to the book or you are not, if not then you deserve to lose your licence, hopefully the ever tighter assessment will weed some out of the system.

As an end note, I do think the EML illuminated is a tough fail, cars with CAN sometimes flash the light with no relevant problem to the powertrain at all! But it is a fail and so it must not pass the test.