Fiat dipped beams not working when engine running! (1 Viewer)

meanders

Funster - Life Member
LIFE MEMBER
Jun 28, 2008
2,458
7,842
Ipswich, Suffolk
Funster No
3,075
MH
C class
Exp
Since 2004
Hi all.

Just spent two hours in Tesco's car park after pulling off on the way to Waldergraves because no dipped beam and it was getting dark.

The dipped beams work perfectly with ignition on until you start the engine. They then go off after a few seconds. If you turn them on with the engine running they come on for 1 - 2 seconds then go off. Breakdown guy couldn't believe it until he tested them himself.

Convinced the relay is OK, but really can't figure out what is going on. I rang the FIAT garage and the technician had never heard anything like it.

Ended up driving home on sidelights with main beam when I could. Rather frightening in places.

Anyone else had the same problem? Any clues as to where to look? Anyone at Waldergraves able to fix it?

If not, its back to the garage next week.... More expense!
 

pappajohn

LIFE MEMBER
Aug 26, 2007
43,207
48,809
Dark side of the moon
Funster No
172
Exp
Since 2005
main lights could be canbus controlled and a fault may exist in the canbus system.

engine off voltage may be ok but start the engine and the volts will rise to 14v +.

could be overloading the canbus circuit for dipped beam.

main dealer should have the equipment to 'talk' to the canbus and retreive fault codes.
 

dogman

Free Member
Oct 24, 2013
549
440
chepstow
Funster No
28,719
MH
Coach Built
Exp
I'm a newbie
Hi all.

Just spent two hours in Tesco's car park after pulling off on the way to Waldergraves because no dipped beam and it was getting dark.

The dipped beams work perfectly with ignition on until you start the engine. They then go off after a few seconds. If you turn them on with the engine running they come on for 1 - 2 seconds then go off. Breakdown guy couldn't believe it until he tested them himself.

Convinced the relay is OK, but really can't figure out what is going on. I rang the FIAT garage and the technician had never heard anything like it.

Ended up driving home on sidelights with main beam when I could. Rather frightening in places.

Anyone else had the same problem? Any clues as to where to look? Anyone at Waldergraves able to fix it?

If not, its back to the garage next week.... More expense!
As a get you out of jail fix, take the connectors out of the 3 pin plug on the back of the bulb/unit, put the high beam cable on the dip beam connector then run on dipped beam only, better than sidelights only.

Subscribers  do not see these advertisements

 

laneside

Funster
Deceased RIP
Aug 14, 2009
2,668
6,276
Oradour sur Vayres
Funster No
7,981
MH
Rapido V66
Exp
nowhere near long enough
This is a long shot and no logically reason why it should work but with my Fiat I can go into menu and switch daylight running lights on and off. Pure illogic but I would try to see if it made a difference
 

dave newell

Free Member
Oct 31, 2008
3,262
4,369
Telford, Shropshire
Funster No
4,733
MH
Home converted PVC
Exp
26yrs
main lights could be canbus controlled and a fault may exist in the canbus system.

engine off voltage may be ok but start the engine and the volts will rise to 14v +.

could be overloading the canbus circuit for dipped beam.

main dealer should have the equipment to 'talk' to the canbus and retreive fault codes.

Its very easy to misunderstand the purpose of CanBus systems and this is a case in point. The CanBus system does not carry any significant current it is simply a data channel. The idea is that instead of lots of big cables carrying high currents around a vehicle there are now just a couple and each unit (could be a light cluster or a seat adjuster or any one of a number of things) has a micro computer connected both to the CanBus (data stream) and the main power carrying cables. Micro computer A (let's say the lighting switch) sends a coded signal along the data bus (CanBus), lighting cluster micro computer recognises this coded signal as an instruction for it to do something etc, etc, etc. The CanBus cannot be "overloaded" as it never carries significant current.

To the OP, as Fiat are notoriously poor with electrickery (almost as bad as they are with gearboxes) and 90+% of electrical problems are poor earth connections I would start with the Earth connections. The engine earth strap is a well known source of problems but mostly with the engine management systems. The vehicle contains numerous micro computers with a variety of names, one of which is often referred to as the "BSI" (Body Systems Interface) this often controls things like seat belt pre tensioners, interior lights and quite possibly the lighting systems. A poor earth on this unit might easily be the cause but it won't show up as that on a diagnostic computer, more likey it will show up as something completely unrelated.

D.
 
OP
OP
meanders

meanders

Funster - Life Member
LIFE MEMBER
Jun 28, 2008
2,458
7,842
Ipswich, Suffolk
Funster No
3,075
MH
C class
Exp
Since 2004
Thanks to you all.

Will look in the 'menu' tomorrow although I don't remember seeing that option on our MH.

Cross wiring is a good idea.... just not a lot of room behind the headlamp units. Also when on main beam only the innermost lens was lit. Not sure on the X250 if the outermost lens has both dip and head. If so, it wasn't working either!

Thanks again.

Subscribers  do not see these advertisements

 

pappajohn

LIFE MEMBER
Aug 26, 2007
43,207
48,809
Dark side of the moon
Funster No
172
Exp
Since 2005
Its very easy to misunderstand the purpose of CanBus systems and this is a case in point. The CanBus system does not carry any significant current it is simply a data channel. The idea is that instead of lots of big cables carrying high currents around a vehicle there are now just a couple and each unit (could be a light cluster or a seat adjuster or any one of a number of things) has a micro computer connected both to the CanBus (data stream) and the main power carrying cables. Micro computer A (let's say the lighting switch) sends a coded signal along the data bus (CanBus), lighting cluster micro computer recognises this coded signal as an instruction for it to do something etc, etc, etc. The CanBus cannot be "overloaded" as it never carries significant current.

To the OP, as Fiat are notoriously poor with electrickery (almost as bad as they are with gearboxes) and 90+% of electrical problems are poor earth connections I would start with the Earth connections. The engine earth strap is a well known source of problems but mostly with the engine management systems. The vehicle contains numerous micro computers with a variety of names, one of which is often referred to as the "BSI" (Body Systems Interface) this often controls things like seat belt pre tensioners, interior lights and quite possibly the lighting systems. A poor earth on this unit might easily be the cause but it won't show up as that on a diagnostic computer, more likey it will show up as something completely unrelated.

D.

agreed Dave, and i could have worded it better.

i should have said overloaded the canbus processor circuit.
 
Sep 23, 2013
2,579
8,604
Lincs
Funster No
28,231
MH
Globecar Campscout
Exp
Since 2008 (started in a VW T4 campervan)
This is a long shot and no logically reason why it should work but with my Fiat I can go into menu and switch daylight running lights on and off. Pure illogic but I would try to see if it made a difference


Thanks to you all.

Will look in the 'menu' tomorrow although I don't remember seeing that option on our MH.
According to my manual, I should be able to do that too. But like meanders, I can't find it in the menu in the van. At the risk of pirating this thread, any hints on how to turn off the daylight running lights in an X250 would be gratefully received.

As to the main topic, earthing faults do cause some very peculiar symptoms, even on pre-CanBus systems. I think that's were I'd start looking too. Never had to work on a CanBus system (yet! - only had mine a month), so can't offer any specific advice I'm afraid.
 
Dec 24, 2009
1,065
15,677
bedworth warks
Funster No
9,712
MH
c class
Exp
2009 previously a tugger for thirty years
We wold be well and truly stuck if that happened to us. We only have lights on or off on our column stalk on our new this year Pilote. Seems a bit odd really that the sidelights only operate when the ignition is switched off.

Hope its an easy fix for you. I sometimes wonder how much technology we really need in our vehicles.

Subscribers  do not see these advertisements

 
Apr 27, 2009
435
218
Departed Cabopino in Oct 17
Funster No
6,478
MH
Dakota
Exp
Fulltiming from 2010- 2017
I'm not a techie by any means, but we had a similar light issue with our Merc Autotrail.

When we indicated left, power dropped off.

We discovered condensation inside the left indicator housing on the left wing. We dried it, put in a small silica pack and its been fine since.

Might work.::bigsmile:
 
Jan 27, 2009
872
3,328
Leyland Lancs
Funster No
5,472
MH
A class
Exp
since 2001
You are not the first

Broken Link Removed

Thanks for that jhorsf. Wonder why Darren has not been on the Forum since with any feedback? Probably forgot once his problem was fixed? :reel: Not just Darren either.:reel:

Subscribers  do not see these advertisements

 

rainbow chasers

Free Member
Oct 30, 2009
3,680
1,725
Mid Cornwall
Funster No
9,132
MH
Various
Exp
9
Bad Earth - you just now need to find where that earth is. Not uncommon for battery terminal earths to get loose - some are not tightened enough due to limited space in these vehicles - pay particular attention to 'extras' that are added on, as these could cause a loose connection. Also check other earth points for fusebox, engine etc.

BSI units are prone to issues, though usually it can be a earth point, relay or the BSI fuse that is faulty or dirty. The Voltage of your engine battery can cause issues with BSI units on HDI engined vehicles as they must be a minimum of 12v. If it is a BSI related issue, I would look at connections, and fuses/relays first before reflashing software. Most BSI issues are fairly simple.

Check the Headlamp relay connections also, as there may be an issue of overheating caused by a dodgy relay which can give this issue,even if the relay appears to be working ok - may not be all the time.

If you have recently, or have fitted immobilisers/tracking devices etc, do check the ignition wiring loom as well for short circuits
 

tonka

LIFE MEMBER
Jul 2, 2008
10,796
21,441
Cannock, Staffs
Funster No
3,141
MH
A class Burstner 800
Exp
Since 2000
Ref the daytime lights on/off switching... It is in the menu but it does not show if you have the engine running.. It confused me at first.. Try with ignition key in and turned but engine not started...
Something like that anyway....
 

aba

Free Member
Oct 27, 2009
2,775
1,112
yorkshire
Funster No
9,066
MH
coachbuilt
Exp
dec 2009
just a quicky have you had a headlight bulb changed recently ???

i ask this as i had a tail light bulb fail and when i replaced it it just flashed on then went off so i swapped it to the other side and it did the same (the fault moved) i then sourced a more expensive bulb and that worked ok.

the only thing i could put it down to was the canbus system wasnt happy with the reading of the bulb an as such decided it was faulty so shut it down.

what happened to a switch and a big wire to the lights it either worked or didn't it was a simple battery-fuse-switch-light and as such easy to find.
these things are getting far too intelligent and if the bulb is 48 watts instead of 50 the system says thats faulty so im not turning it on.

Subscribers  do not see these advertisements

 
Mar 21, 2009
1,367
874
Harwich, Essex
Funster No
5,989
MH
C Class
Exp
4 years
We has a similar problem a few weeks after we bought our Fiat motorhome and on our first trip out in it to Val Thorens we ended up having to tailgate Haganaps along the motorway as we lost headlights when the engine warmed up:Eeek::Eeek::Eeek: We had to ensure that our home journey was carried out in daylight.
Anyway when we got home we found that one of our customers had bought his motorhome into our garage with the same fault. After extensive investigation an auto electrician traced the fault to the the BSI unit which controls all the light switching behind the fog light switches in the dash. This was replaced and cured his fault.
So we took our van to the same auto electrician and he confirmed it was the same unit on our van that was faulty so we had it replaced and we haven't had a problem since then (2 years ago).
I think the whole job cost about £295 but that was not done at a main dealer it was an independent electrician.
I'm not saying that this is your fault but just that it may be worth investigating this unit?
Jacky
 
Last edited:

laneside

Funster
Deceased RIP
Aug 14, 2009
2,668
6,276
Oradour sur Vayres
Funster No
7,981
MH
Rapido V66
Exp
nowhere near long enough
Just had a thought----I had better check mine we have done 13, 000 miles now and believe it or not we have never been out on the road in the dark yet
 
OP
OP
meanders

meanders

Funster - Life Member
LIFE MEMBER
Jun 28, 2008
2,458
7,842
Ipswich, Suffolk
Funster No
3,075
MH
C class
Exp
Since 2004
RESOLVED.:Smile:

After 8 days at the Fiat dealer and with support from the Fiat motorhome support line in Italy, it was finally fixed.

It was the 'BODY COMPUTER'. After a hard reset and both keys recoded, its absolutely fine.

They tried changing the stalk, but that made no difference. All earth straps were checked and all fine. Italy suggested the hard reboot. If that hadn't worked it would have been a new computer. :-(

I've found four other people who have had the same problem on various forums, but no-one posted the fix, so hopefully this will help others. Not something you can fix yourselves, but at least you can push them in the right direction.

The good news is that despite spending many hours, i was only charged the hours labour for the reprogramming. :thumb:
 

jhorsf

Free Member
May 15, 2009
9,130
8,045
DERBYSHIRE
Funster No
6,717
MH
ih oregon
Exp
2000
in the info I posted above it tells you how to reset the body computer
 
OP
OP
meanders

meanders

Funster - Life Member
LIFE MEMBER
Jun 28, 2008
2,458
7,842
Ipswich, Suffolk
Funster No
3,075
MH
C class
Exp
Since 2004
While I'm grateful that you posted the reset instructions, that didn't work and it needed a 'hard reset'. This means the keys were needed for recoding and the ISR code was required to enable this to happen.

Unfortunately I now have fairly severe mobility problems so struggle to do things myself so it worth c£100 for someone else to do it.

Subscribers  do not see these advertisements

 

Ianjoh

Free Member
Aug 5, 2021
3
2
Funster No
83,244
MH
Carioca 656
Hi
Just picking up on an old thread.
I have exactly the same problem, also the EML (warning) light is on but reading the code I get No Emission code found, resetting the light will not clear it either.
As the OP is Ipswich based I am wondering which dealer he took it to as I am near Bungay.
Thanks
Ian
 

Eggs

Free Member
Jan 3, 2018
1,633
2,934
Suffolk
Funster No
51,836
Hi
Just picking up on an old thread.
I have exactly the same problem, also the EML (warning) light is on but reading the code I get No Emission code found, resetting the light will not clear it either.
As the OP is Ipswich based I am wondering which dealer he took it to as I am near Bungay.
Thanks
Ian
I can't help with Ipswich, this fella knows his stuff, just up the road in Bury-St-Edmunds.


I wonder when an Ipswich dealer was mentioned was it Stowmarket Caravans? If so, they are long gone.
 

Jaws

LIFE MEMBER
Sep 26, 2008
23,821
71,977
Thetford Norfolk
Funster No
4,189
MH
C class, Chieftain
Exp
since 2006 ( I think ! )
Hi
Just picking up on an old thread.
I have exactly the same problem, also the EML (warning) light is on but reading the code I get No Emission code found, resetting the light will not clear it either.
As the OP is Ipswich based I am wondering which dealer he took it to as I am near Bungay.
Thanks
Ian
meanders .. One for you mate :)

Subscribers  do not see these advertisements

 
OP
OP
meanders

meanders

Funster - Life Member
LIFE MEMBER
Jun 28, 2008
2,458
7,842
Ipswich, Suffolk
Funster No
3,075
MH
C class
Exp
Since 2004
Hi Ianjoh

The reset done a couple of times worked for a short period including the useless main dealer in Bury. Eventually took it to Salmons at Weeley who were great. After involving Fiat Camper Support it was eventually confirmed as a fault in the ECU computer. Reburning it solved the issue for a few more weeks but the problem returned. Fiat Italy said the unit had to be replaced but by then it was well out of warranty. I did get a discount but can't remember how much. It still cost me a few hundred if I remember correctly.

Like all intermittent faults, a right PITA.
 

Ianjoh

Free Member
Aug 5, 2021
3
2
Funster No
83,244
MH
Carioca 656
Thank you for the replies.
It is booked in with Desira at Diss for a code read and I will ask them to reset the ECU but I am now wondering if it is worth the wait and expense for it to possibly reoccur soon after. I think it was a bad battery over the winter that corrupted the memory or damaged something.
Another option is to buy a used ECU with keys and just swop it over although I think the cluster is coded to the ECU too.
Thanks
 

Ianjoh

Free Member
Aug 5, 2021
3
2
Funster No
83,244
MH
Carioca 656
Just an update. Had it booked in with Desira at Diss but while waiting for the date to arrive I done some googling into the problem and came across Multiecuscan software, I had a spare VAG KKL lead so I downloaded it to an old vista laptop, paid $50 for the licence and bingo! It found codes that my handheld failed to. Eml light was for the cooling fan, I traced that to a corroded wire in the loom from the ECU under the passenger headlamp. The headlamp switching off problem has also disappeared which is good for the mot retest but at the moment I don't trust it for driving in the dark!

Subscribers  do not see these advertisements

 

Join us or log in to post a reply.

To join in you must be a member of MotorhomeFun

Join MotorhomeFun

Join us, it quick and easy!

Log in

Already a member? Log in here.

Latest journal entries

Funsters who are viewing this thread

Back
Top