2004 leon fr tdi - engine management light is on

Feb 1, 2007
1,602
1
Nottingham
Hmmm. Reading this thread with some interest. As far as I can tell I don't have a 'real' glow plug issue BUT have had vag-com faults that suggest glowplug issues with wiring faults to glowplugs 2 and 3 - it's a very long story, and is well detailed by Fester and I in the LCR twin fans thread around page 7.

When the warning light first came on the VAG specialist I went to said they wouldn't touch glowplugs because they were "tricky to do" and they'd have to refer me to "an engine specialist" for "a days work" to get them replaced. Smelled more than a little fishy at the time, and having read this thread I'm wondering were they attempting to fob me off?

Interesting that the wiring loom for glowplugs is under the battery compartment... as that's where the fans issue fix unit goes that's thought to be interfering and causing intermittent glowplug warning lights for Fester and I currently.

The routing of the wiring under the battery has nothing to do with the fan problem. I have just replaced the loom for the glow plugs as I had the wiring fault code to plugs 2 and 3. The fault has gone now so I am confident I have sorted my problem. Care is needed when replacing the plugs although its easy to do. It is however easy to cross thread the cylinder head with the new plug if the angle of fitment is incorrect. If anybody reuires a step by step guide to replacing the loom let me know!
Glynn
 
Feb 1, 2007
1,602
1
Nottingham
Easy to change and can supply all the parts numbers will post later when I get home. Be advised that pre o4 leon tdi do not have a glow plug pre heater system and as such have only 2 wires in the loom for the plugs. Mine is post 04 and has 4 wires in the loom so the part number will be different. The part number for the loom is located on the back of the bridge, this is the plastic connecto to the plugs themselves, so its easy to pull off the plugs to get the number. The price is the same for both types of loom at about £19 plus vat.
Anybody living near me with the problem can come over and I will show them how to do it!
Glynn
 

cuprakitty

Active Member
May 1, 2007
85
0
Wolves, West Midlands
The routing of the wiring under the battery has nothing to do with the fan problem...

I may have been misunderstood - I wasn't saying the fan problem itself was related to the wiring. As you say, it's not! There's a third party fix for the fan problem (the Nime box) - an electrical unit that fits under the battery compartment. BUT in Leons it's causing electrical 'gremlins' - in Festers and my TDIs its causing 'fake' glowplug faults; in other models it's the ABS/TCS that gets lights/faults. The suspicion is it's interfering with wiring in its vicinity and triggering the warning lights and fault codes in vag-com.

This thread likely explains why glowplug errors cropped up for us - the wiring for the glowplugs is sat right next to the Nime box! Easy target for electrical gremlins.
 

cuprakitty

Active Member
May 1, 2007
85
0
Wolves, West Midlands
they can't be very good vag specialists if they wont change glow plugs

I suspect the 'problem' alluded to was more fundamental, as they're usually pretty good. I got the distinct impression something bad had happened when they'd done some glowplug work in the past and they'd been stung as a result. Such that they won't touch glowplugs with a barge pole now.
 

mono_18

Guest
Hi Glynnd,
I would like a step by step guide 2 replacing the loom please, as I have the same problem with the wiring to all 4 glow plugs and these have been replaced and the light keeps on coming on.
Thanks
 

mono_18

Guest
cheers, really starting to annoy me, everytime it's cold on comes the light.
 

whitz end

Guest
Good evening. I am a first time poster. Found this thread thro google, i have had the management light up on the dash (leon fr 150) and it was diagnosed as a fault on cylinder 4 glow plug or the wiring loom or the control module. I found a faulty glow plug but replaced all 4 while it was in bits. I tested them all as i refitted then. The management light is still on. Does anybody know if the fault needs to be reset by being put back on the computer or should I keep looking. thanks in advance
 

whitz end

Guest
cheers....took the car back yesterday and had it reset. it seems ok and i definatly had a faulty glow plug
 

stevei'D

Active Member
Jul 22, 2008
96
0
Reading with intrest, my experience

I have a 06 FR+ and have had a similar prob. About 4months ago got in the car on a very cold morning and started car, EML cam on straight away. Took it to dealer and it read a sporadic fault with the glow plugs/control module. Car drove fine so was told if it happens again pop in. Well 4 days ago same thing happened and same fault showed. The garage are replacing the control module under warranty. They mentioned they have done a few of these but not many as to cause any concern.

I raised the point that on both occasions i was in a bit of a rush and more or less turned the key straight away without waiting for glow plug light to go out. I mentioned that my old focus diesel would always need a 4-5second wait especially when cold. The garage said that this should not be the case with modern diesels as when you unlock the vehicle the control unit begins to ignite/warm up the glow plugs therefore there is no wait or a nano second wait for the glow plug light to extinguish, hence starting it up staright away should not be any problem at all.

On both occasions the car started normally, no extra "chugging" or "coughing" before firing up, sorry best terms i could use to describe.

Again since the EML has been extinguished no probs, even on the cold mornings weve had.

New module being fitted thurs 23rd so all good.

As a further point the grage (Westerham Seat) has been spot on. Both times getting me in quickly on the day to have the fault read and dealt with and courtesey car offered straight away. Recently had a service too, I stated they could have the car all day, come 13:00hrs a txt from the garage saying something along the lines of "car all done no faults ready to collect", which i though was brilliant and a good idea.

Steve
 

whitz end

Guest
cheers mate
the garage that plugged my car in to do the diagnosis are happy to keep reseting the fault while i keep trying to cure it (or so they say). they have said that i will only have to pay again if i get up a new fault.
i know the guy who owns the place and he is spot on. it appears as though the new glow plugs have cured my eml for the moment
 

strugers1

Guest
my coil light has come on and it flashes what does that mean??it rives fine starts fine??is that glow plugs??
 

whitz end

Guest
When my glow plug light was flashing it was a faulty break light switch so its worth having a quick look round the car and check to see if you have any brake lights before having it diagnosed. I got a break light switch for under a tenner and when the brake lights were working the warning light reset itself. I dont know how true it is but i was told that a flashing glow plug light could be anyone of about 150 possible causes. I anm sure that i have read about this in another thread on this site, hope this helps
 
Jan 22, 2007
2,074
0
some may say lala land....
right, i have this issue and no vag-com so will be changing the loom & plugs this weekend, on the off chance it fixes it...

As such, glynnd;
Do you have the Guide a complete stupid no brain newbie can follow?
Do you know if any specific tools are needed as I will need to purchase them as well?

I'll be ordering today at lunchtime, so any further pointers are accepted....

[edit]
that's the bits ordered and should collect on friday to fit saturday
now to purchase vag-com & cable etc so can check error and clear it after all done
[/edit]
 
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