Electrics: - Fog Lights Not working

gatos · May 10th, 2010, 22:18

My car is a 2002 1.9 diesel S40 Sport T4.

I have just noticed that my fog Lights are not working at all. I am lucky enough to have a second Volvo S40 2000 phase 2 and I just swapped the control unit/switches on the right hand side of the steering wheel but no luck either. Now it is possible that both units are not functioning properly, but the odds for that are a bit too high. I looked at the Haynes manual and it was ............ well useless. I also had a look at VADIS that a friend of a friend of a friend has

but could not find any useful info there either. Obviously I have checked the fuses etc and all seem to be fine.

Any ideas what else can I look for. Is there a relay for the fog lights and if yes, where is it located?

I need your brains please.

Baffler · May 11th, 2010, 11:20

Hi Gatos,

As far as I know the front fogs are activated through the CEM (Central Electronic Module) and the relay is located within this unit. Is the rear fog light working? Before you go pulling out the CEM did you test the bulbs to see if they are lighting up ok? Sometimes a bulb filament can look ok but is broken in an obscure place...

There was a chap (Gav25 ?) on here a few weeks back who had a similar problem with the front fogs on a phase 1.5 S40. Turned out it was the CEM.

gatos · May 11th, 2010, 11:27

Thanks baffler. I checked bulbs and they are fine. I am going to use my spare CEM and see if it works. If not..... I will have to retrace the cables for faults.

Will let you know of the result tonight

grass hopper · May 11th, 2010, 12:21

had one with the same fault,was found to be a corroded wire under the radiator,a live feed was missing at the switch pack,i think also the front side lights and side markers stopped working also.

gatos · May 14th, 2010, 00:23

Still havent had a chance to look into it. I looked around for any corroded cables but all seemed to be fine. I will try to replace the CEM this weekend and see if it makes a difference. The other thing I notice tonight was that none of the lights in the control unit/switches on the right hand side of the steering wheel are illuminated... More to investigate this weekend...

gatos · May 17th, 2010, 18:31

OK this is getting more interesting now... Both high beams stopped working too......

I swaped the spare CEM I had but no difference. Which means that either both CEMs are faulty, or that I have a sort somewhere in the wiring.

Also when i pull the high beam lever towards me, there is no blue light coming up in the instrument panel.

Just to clarify something, when i engage the high beams, i can hear a click from the CEM. Does that mean the relay is functioning properly, or not necessarily?

aanderson · May 10th, 2015, 18:26

I have two Volvo 1.9 diesel V40'S (years 2002 & 2003)
The 2002 has developed a fault with some of its lights. The side lights & front & rear fog lights no longer work and a MOT is due shortly.
To clarify the side lights: only the two rear lights in the tailgate work (outer ones don't), the brake lights, number plate lights & reversing lights all work.
The front small side lights don't work, Dip & Main beam are ok.
The small green LED on the Main Light Switch doesn't come on when turned!
Its not the fuses and bulbs and have swapped the Main Light Switch and the Central Electronic Module from my other V40.
Apart from the wiring harness under the radiator are there any other areas or a relay somewhere I need to check first?

bobbytodd · Aug 16th, 2015, 09:58

aanderson did you ever get yours sorted? because im in exactly the same situation as you no front rear fogs and no fog symbols on the dash
ive tried 3 different cem's and still cant get the front or rear fogs to work.this Volvo is seriously starting to **** me off
ive also had the radiator out and the loom is fine and ive also checked under the wheel arch.

gatos · Aug 16th, 2015, 10:57

Quote:

Originally Posted by bobbytodd

aanderson did you ever get yours sorted? because im in exactly the same situation as you no front rear fogs and no fog symbols on the dash
ive tried 3 different cem's and still cant get the front or rear fogs to work.this Volvo is seriously starting to **** me off
ive also had the radiator out and the loom is fine and ive also checked under the wheel arch.

Have you tried a replacement switch? Also, have you checked the fuses?

GaryS40 · Aug 16th, 2015, 11:51

Quote:

Originally Posted by gatos

My car is a 2002 1.9 diesel S40 Sport T4.

I have just noticed that my fog Lights are not working at all. I am lucky enough to have a second Volvo S40 2000 phase 2 and I just swapped the control unit/switches on the right hand side of the steering wheel but no luck either. Now it is possible that both units are not functioning properly, but the odds for that are a bit too high. I looked at the Haynes manual and it was ............ well useless. I also had a look at VADIS that a friend of a friend of a friend has

but could not find any useful info there either. Obviously I have checked the fuses etc and all seem to be fine.

Any ideas what else can I look for. Is there a relay for the fog lights and if yes, where is it located?

I need your brains please.

Just saw this one, Alex.

What is a diesel T4?

Hybrid?

Diesel that looks like a T4?

Gary

May 10th, 2010, 22:18	#1
gatos Premier Member Last Online: Nov 15th, 2022 21:34 Join Date: Apr 2010 Location: London / Essex	Fog Lights Not working My car is a 2002 1.9 diesel S40 Sport T4. I have just noticed that my fog Lights are not working at all. I am lucky enough to have a second Volvo S40 2000 phase 2 and I just swapped the control unit/switches on the right hand side of the steering wheel but no luck either. Now it is possible that both units are not functioning properly, but the odds for that are a bit too high. I looked at the Haynes manual and it was ............ well useless. I also had a look at VADIS that a friend of a friend of a friend has but could not find any useful info there either. Obviously I have checked the fuses etc and all seem to be fine. Any ideas what else can I look for. Is there a relay for the fog lights and if yes, where is it located? I need your brains please.

May 11th, 2010, 11:20	#2
Baffler Premier Member Last Online: Yesterday 21:18 Join Date: Dec 2002 Location: Co. Limerick, Ireland	Hi Gatos, As far as I know the front fogs are activated through the CEM (Central Electronic Module) and the relay is located within this unit. Is the rear fog light working? Before you go pulling out the CEM did you test the bulbs to see if they are lighting up ok? Sometimes a bulb filament can look ok but is broken in an obscure place... There was a chap (Gav25 ?) on here a few weeks back who had a similar problem with the front fogs on a phase 1.5 S40. Turned out it was the CEM. __________________ Liam... '96 854 TDI SE, '99 V70 2.5D S, '05 C70 2.0T Collection, '05 S80 2.0T SE, '15 V70 D4 SE Lux Nav.

May 11th, 2010, 12:21	#4
grass hopper Premier Member Last Online: Mar 18th, 2011 13:38 Join Date: May 2009 Location: grassmere!	had one with the same fault,was found to be a corroded wire under the radiator,a live feed was missing at the switch pack,i think also the front side lights and side markers stopped working also. __________________

May 10th, 2015, 18:26	#7
aanderson New Member Last Online: Oct 10th, 2023 10:49 Join Date: Jan 2011 Location: wiveliscombe	Side lights & Front & Rear fog lights not working I have two Volvo 1.9 diesel V40'S (years 2002 & 2003) The 2002 has developed a fault with some of its lights. The side lights & front & rear fog lights no longer work and a MOT is due shortly. To clarify the side lights: only the two rear lights in the tailgate work (outer ones don't), the brake lights, number plate lights & reversing lights all work. The front small side lights don't work, Dip & Main beam are ok. The small green LED on the Main Light Switch doesn't come on when turned! Its not the fuses and bulbs and have swapped the Main Light Switch and the Central Electronic Module from my other V40. Apart from the wiring harness under the radiator are there any other areas or a relay somewhere I need to check first?

Aug 16th, 2015, 09:58	#8
bobbytodd Junior Member Last Online: Oct 28th, 2015 20:57 Join Date: Jul 2014 Location: cumbria	aanderson did you ever get yours sorted? because im in exactly the same situation as you no front rear fogs and no fog symbols on the dash ive tried 3 different cem's and still cant get the front or rear fogs to work.this Volvo is seriously starting to **** me off ive also had the radiator out and the loom is fine and ive also checked under the wheel arch. Last edited by bobbytodd; Aug 16th, 2015 at 10:00.

May 11th, 2010, 11:27	#3
gatos Premier Member Last Online: Nov 15th, 2022 21:34 Join Date: Apr 2010 Location: London / Essex	Thanks baffler. I checked bulbs and they are fine. I am going to use my spare CEM and see if it works. If not..... I will have to retrace the cables for faults. Will let you know of the result tonight

May 14th, 2010, 00:23	#5
gatos Premier Member Last Online: Nov 15th, 2022 21:34 Join Date: Apr 2010 Location: London / Essex	Still havent had a chance to look into it. I looked around for any corroded cables but all seemed to be fine. I will try to replace the CEM this weekend and see if it makes a difference. The other thing I notice tonight was that none of the lights in the control unit/switches on the right hand side of the steering wheel are illuminated... More to investigate this weekend...

May 17th, 2010, 18:31	#6
gatos Premier Member Last Online: Nov 15th, 2022 21:34 Join Date: Apr 2010 Location: London / Essex	OK this is getting more interesting now... Both high beams stopped working too...... I swaped the spare CEM I had but no difference. Which means that either both CEMs are faulty, or that I have a sort somewhere in the wiring. Also when i pull the high beam lever towards me, there is no blue light coming up in the instrument panel. Just to clarify something, when i engage the high beams, i can hear a click from the CEM. Does that mean the relay is functioning properly, or not necessarily?

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