right lowbeam won't work
 

I have a 2003 s40, and about a week ago my right lowbeam headlight went out. I've replaced the bulb and checked the fuse, and i can't seem to find the problem. Any help would be appreciated.

When you turn the light on, is the fuse getting power? If so, how about the bulb itself?

Is it the stock bulb type or did you put an hid kit on?

the fuse is only getting about 8V. The socket gets 11V when the bulb is out. With the bulb in, it gets 0V. And everything involved is stock.

It might be a bad CEM/Central electronic module. The bulb gets direct power from the CEM. I've replaced alot of them

CEMs are getting hard to find. Common failure of a single lowbeam can be tied to a relay failure...a $2.00 part commonly found in an electronics store. 12 Volt DC, 10 to 15amp, SPDT, 5 pin configuration. Heat up the bad one to remove, and solder in the replacement.

If you have pictures and a part number we would be grateful. Sounds like a good alternate fix rather than buying used or new.

Bro Hudini~

Always good to hear from you. I spent hours on several Volvo Forums and found the Brits (UK) to be wonderfully resourceful and resilient DIY ers---The CEM has two relays---each one controls the left and right low beam headlights, and the relays fail at an alarming rate. Most scavange the CEM's at the wrecking yards, but several owners have de-soldered the failed part, and soldered in a replacement--

In the USA, there is an online supplier...web addy is www.digikey.com The relay part number is 255-1240-ND. Cost is $1.72 (USD) plus shipping, and unlike the UK, there is no mininum...UK min. = 20 relays. Go figure. 5 pin relays are universal, and a few posters said the fit was perfect, and the soldering was uneventful...but use a cheap de-soldering pump (check out Google) to keep it clean.

Btw...once you access digikey's website and type in the PN (part number), scroll to the REAL part number you need....JSM1-12V-5

IF your squeamish about removing your CEM, (aka ECM)...the Brittish forum has a beneficial poster who has a great link you can download....

How did we cope before the Internet? Listen up....i just ordered my relays yesterday, but I intend to take pics and post my results asap. My confidence is HIGH! This Forum could be a great resource...but you Volvo Owners are gonna HAVE to get involved. Peace to all.

Relays arrived in two days. Removal of the CEM was a snap. HOWEVER....as careful and uber determined as I was to access the PCB (printed circuit board)---I failed to split the case. It must be press fit together...I was able to separate each side by 5-7mm, but the bugger was tighter than a clam. I am going to take it to a shop and have them open the @$&*%$ thing for me...IF they are even willing. ACCK!

Found 20 on ebay. There's one for $50 & free shipping. I'm tempted to buy it just to have a spare. Nothing wrong with mine but if this is a common failure then I'll be ready. I remember a somewhat similar issue with my Saab 900. It was a "lighting control relay" and it was $147 :eek: Too bad there wasn't a cheap fix for it.

Hallejluah!!! Decided to give another shot at separating the CEM case. Those Volvo buggers hid the philips tip screw under the ID decal. Lovely! De-soldering and removing the bad relay took @ 1 hr, and was extremely difficult, but I did actually swap it out, and lo and behold---both headlamps are operational. Thankyou, LORD, and many thanks to the posters on three Volvo Forums without whose shared knowledge and experiences, I would never have prevailed.

I'm stuck here in China with no access to VIDA. Where exactly is the CEM mounted?

My 2000 S40, left hand drive CEM is located on the left hand side well below the dash board, very close to the hood release. You need to remove four philips head screws (the lowest left screw is coverede by a piece of trim, easily removable) holding the cover in place. The CEM is mounted with two screws on the left side, and a shiny metal tab on the upper right side. There are four wire harnesses that need to be disconnected...in the center of each harnesss connector is a tab that MUST be depressed to disconnect. The UK volvo Forum has VIDA links for a visual, but they call the CEM = ECM or sometimes ECU. Just make sure you disconnect the negative battery cable prior to work, and position the ignition switch to II prior to hooking the battery back up. Of course, have your radio reset code at the ready, and reset your clock.

what is the brittish link that show how to replace the relays

Google "Volvo Forums".....near the top on the first page there will be a UK Forum you should click. Then puruse through S40 posts, and search for headlamp issues. The guy who posted the pics identified the proper one.

Johnny,
I had just ordered new relays and as my head hit the pillow I remembered that in your answer you had mentioned the radio reset code. I have the code for my car, but a few years back we put in an aftermarket radio. Does that mean I'm dead in the water??

Aftermarket radios have reset codes? Mine doesn't.

No, that's my question. I guess I should have asked what are the radio reset codes for? Just the radio? (I know, after looking at that, it does seem kind of like a stupid question)

I was under the assumption that the radio reset codes were for more than just the radio.

And why should the ignition switch be "set to II"?

and just for general knowledge, I did (or actually my son did) hooked the right light up to the left light, and they both work.

My new relays were shipped today. I ordered 4 just to be safe, the shipping was more than the relays.

Thanks for all the ideas on this, seems like a lot of work just to keep the lights on!

I believe the radio reset code was intended as an anti-theft deterrent and only controlled the radio. Doubtful that any aftermarket manufacturer would have one.


Jury rigging (what your son did) might/might not work long-term...but if the Volvo engineers had one relay per low beam lamp, you have to wonder why. My repair remains effective to this day.


Yes, it was a Herculean effort (mostly research) to keep the lights on while avoiding the Stealership---and it is illegal and unsafe to only have one low beam burning. When you effect the proper repair, you will feel empowered.


Honestly, I have forgotten why the ignition switch is turned to position II but knowing myself....I urge you to double check. These cars are weird!

Addendum---Splitting the CEM case. Those buggers at Volvo placed a sticker over a Philips head screw that held the case together.