M54 EML Light - Limp or not?
M54 EML Light - Limp or not?
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Discussion

ads_4116

Original Poster:

151 posts

117 months

Friday 8th October 2021
quotequote all
Hi all, collecting a bought unseen E39 with the M54 engine on Sunday with the EML light on, (not the engine management light), a light with the letters "EML" which according to my research is something to do with the throttle management system.

Now, with this EML light on, am I guaranteed that this will definitely be in limp mode, or is there any possibility that it may not be in limp mode and perfectly driveable? Its a probate sale, and the sellers son don't know much about it. Its been sat for the past 5 months in storage, but has been started recently with no issues, but not driven. Has 5 months MOT on it which is a bonus.

I know the above might sound vague, but trying to work out whether it's an absolute definite "need a trailer", or whether there is a small possibility I could just simply drive it home.

Cheers.

SteBrown91

3,149 posts

159 months

Friday 8th October 2021
quotequote all
It could be anything from a duff exhaust sensor to something major - I would get a Carly adaptor and scan it hopefully it will just be a sensor and will be fine to drive.

d_a_n1979

13,854 posts

102 months

Friday 8th October 2021
quotequote all
ads_4116 said:
Hi all, collecting a bought unseen E39 with the M54 engine on Sunday with the EML light on, (not the engine management light), a light with the letters "EML" which according to my research is something to do with the throttle management system.

Now, with this EML light on, am I guaranteed that this will definitely be in limp mode, or is there any possibility that it may not be in limp mode and perfectly driveable? Its a probate sale, and the sellers son don't know much about it. Its been sat for the past 5 months in storage, but has been started recently with no issues, but not driven. Has 5 months MOT on it which is a bonus.

I know the above might sound vague, but trying to work out whether it's an absolute definite "need a trailer", or whether there is a small possibility I could just simply drive it home.

Cheers.
Really the codes need to be read (INPA, Carly for. BMW, Foxwell scanner etc)

As above it could be a vac leak, failed MAF, spilt intake boot letting air in after the MAF, failing/failed cam/crank sensor etc)...

Basically, it could be all sorts!

If you can, ask the seller to take it for a drive, or go & drive it yourself if it's not too far away...

Only way to tell really

But these don't really do a limp mode unless it's a box issue

g3org3y

22,501 posts

221 months

Friday 8th October 2021
quotequote all
Echo the above, could be a multitude of reasons for the EML, the car might run fine, it might have a misfire (or worse).

Can't tell unless you chuck it on a code reader.

ads_4116

Original Poster:

151 posts

117 months

Friday 8th October 2021
quotequote all
Thanks for your replies!

I've ordered a Carista OBD scanner, been recommended by an old work colleague. What are your thoughts on a Carista scanner?

Also, I've asked the seller to take it out for a drive tomorrow to see what happens. Hoping the EML is an easy fix, but as you guys say, it could be a number of things. Scanner won't arrive for another 3 or 4 days though.

Krikkit

27,938 posts

211 months

Friday 8th October 2021
quotequote all
Not sure if it's the same on the E39, but on my E46 the EML light isn't used for normal trouble codes, but something more vital not working correctly, as you say most likely a throttle by wire issue I believe.

Last time I saw it was when I'd not plugged the throttle body back in correctly after having it off.

INPA/Clarista/BMW scanner will tell all though smile

helix402

7,913 posts

212 months

Saturday 9th October 2021
quotequote all
The M54 can go into limp mode if the battery is failing. I fixed one that had numerous throttle codes stored which were all due to a weak battery.

lufbramatt

5,687 posts

164 months

Saturday 9th October 2021
quotequote all
helix402 said:
The M54 can go into limp mode if the battery is failing. I fixed one that had numerous throttle codes stored which were all due to a weak battery.
Yep they are very sensitive to low battery voltage. Give it a good charge and see if it sorts it.

ads_4116

Original Poster:

151 posts

117 months

Sunday 10th October 2021
quotequote all
I've collected the car and it seems to drive perfectly fine! The "EML" light is now off but the actual engine management light is now on.

Scanned it using an OBD scanner and the following shows:

P0444
Evaporative emission system purge control valve circuit open

Can someone tell me in layman's terms what does this mean?

Many thanks!

g3org3y

22,501 posts

221 months

Sunday 10th October 2021
quotequote all
^Good news! thumbup

Sounds like it could be the EVAP valve (located under the bonnet). I don't believe the part is expensive, had it replaced on my X5 when it threw up the 'check engine' light (car was running absolutely fine). IIRC the code can also be related to a bad fuel cap that isn't sealing properly.


Edited by g3org3y on Sunday 10th October 17:11

ads_4116

Original Poster:

151 posts

117 months

Sunday 10th October 2021
quotequote all
Thanks for the advice!!

Will order a fuel cap first from the stealers to see if that rectifies it, if not EVAP valve it is. I've been researching online what you said about the fuel cap, so had a look at the one on the car and the seal is shot. So hoping its a simple fix with this.

Thank you once again for all your help and advice, someone on these forums always has the answer.

Jakg

4,050 posts

198 months

Sunday 10th October 2021
quotequote all
ads_4116 said:
I've collected the car and it seems to drive perfectly fine! The "EML" light is now off but the actual engine management light is now on.

Scanned it using an OBD scanner and the following shows:

P0444
Evaporative emission system purge control valve circuit open

Can someone tell me in layman's terms what does this mean?

Many thanks!
I *think* evap purge valve = fuel vent valve - it opens to vent vapour from the fuel system back into the inlet.

My M54 engined Z4 was a pain to fill with fuel so I changed it, it was like £20 and very simple to fit but be very careful not to pull the hose it connects to off the other end on the inlet manifold, it's not fun to refit.
Obviously you probably want to check the battery and clean the connections first...

ads_4116

Original Poster:

151 posts

117 months

Monday 11th October 2021
quotequote all
Interestingly, the engine management light has now switched off this afternoon and all is well!

No idea why or how, and also the power delivery mid rev range seems to be better too. Will still order a new fuel cap anyway as the seal is shot just in case.

Oh, and by the way, I have got myself an absolute stonking bargain of a car, bought unseen over the phone and I was expecting a major shed. Turned out to be the complete opposite.

2002 525i SE Auto
141k miles
1 private owner from brand new
Aspen silver with black leather
Huge file of service history including the original purchase invoice. Serviced by BMW till 2011 and independent since every year.
11 months MOT
Michelin tyres all round - 4mm front, 7mm rear
Completely standard vehicle
Completely unused toolkit/torch/first aid kit
No dead pixels on dash
Fully working air con
NO oil leaks!!!

Bad points:
Was told the "EML" light was on. Car has been sitting for a long while. This then changed when I picked it up to the actual engine light which after a lengthy drive, has now gone off. Woo!
The OBC thinks the bootlid is open, however is actually closed. I think the issue is a broken wire in the bootlid (common issue).
Rear parking sensors temperamental (Common E39 issue).
Large scratch on osr door (its 19 years old).
Headlights are cloudy (going to order a resto kit).
Headlight bulbs are shockingly rubbish, need to upgrade these so I can actually see when driving at night.
Very slight wear to the drivers seat base but not the bolster (needs treating).
Few very slight scuffs on the corner of the bumpers.

So how much did I spend on this....

£500!

Yes, I spent the total sum of £500 with a long MOT and it just drives and looks incredibly well. I bought it unseen thinking, I'll drive it for a few months expecting an absolute shed, and then weigh it in for scrap once it goes bang. But now that I've got it, no way! This is a keeper.

d_a_n1979

13,854 posts

102 months

Monday 11th October 2021
quotequote all
ads_4116 said:
Interestingly, the engine management light has now switched off this afternoon and all is well!

No idea why or how, and also the power delivery mid rev range seems to be better too. Will still order a new fuel cap anyway as the seal is shot just in case.

Oh, and by the way, I have got myself an absolute stonking bargain of a car, bought unseen over the phone and I was expecting a major shed. Turned out to be the complete opposite.

2002 525i SE Auto
141k miles
1 private owner from brand new
Aspen silver with black leather
Huge file of service history including the original purchase invoice. Serviced by BMW till 2011 and independent since every year.
11 months MOT
Michelin tyres all round - 4mm front, 7mm rear
Completely standard vehicle
Completely unused toolkit/torch/first aid kit
No dead pixels on dash
Fully working air con
NO oil leaks!!!

Bad points:
Was told the "EML" light was on. Car has been sitting for a long while. This then changed when I picked it up to the actual engine light which after a lengthy drive, has now gone off. Woo!
The OBC thinks the bootlid is open, however is actually closed. I think the issue is a broken wire in the bootlid (common issue).
Rear parking sensors temperamental (Common E39 issue).
Large scratch on osr door (its 19 years old).
Headlights are cloudy (going to order a resto kit).
Headlight bulbs are shockingly rubbish, need to upgrade these so I can actually see when driving at night.
Very slight wear to the drivers seat base but not the bolster (needs treating).
Few very slight scuffs on the corner of the bumpers.

So how much did I spend on this....

£500!

Yes, I spent the total sum of £500 with a long MOT and it just drives and looks incredibly well. I bought it unseen thinking, I'll drive it for a few months expecting an absolute shed, and then weigh it in for scrap once it goes bang. But now that I've got it, no way! This is a keeper.
Sounds to me more battery/electricals related now than anything else

As already said above; these cars do not like low voltages; so ensure the battery is good (if not buy another and go for an 019 - as big as you can fit - Bosch, Yuasa, Exide etc) and keep the battery tip top. An Italian tune up once a week is well advised wink

Re oil leaks and none; meh... Fibber tongue outbiggrin Pics or it never happened laugh

Olivergt

2,267 posts

111 months

Tuesday 12th October 2021
quotequote all
d_a_n1979 said:
...

Re oil leaks and none; meh... Fibber tongue outbiggrin Pics or it never happened laugh
I know it's hard to believe, I have a 2003 E46 with no oil leaks as well. (It has had the rocker cover and the oil filter housing done, but the sump gasket is remarkably oil free).