2001 s40 1.9T

Drivers side low beam is out. New bulb - checked fuse. With bulb out, volt meter on connector reads 11.4V. Plug the bulb in and it won't light. I get 0v across the bulb spade lugs with the bulb partially inserted. I checked these results against the passenger side and I get the same voltage with the bulb unplugged but still get 11.4v with the bulb partially plugged in (and pass. side works). Does this sound like a CEM problem? I've checked the forum and there are many headlight problems but they all seem to have 0v on the plug. Anyone seen this before?

thanks

 

If it is any consolation, I should have checked the forums. I just asked the same question.... I am no electrician, so I am hoping someone here can answer the question.

Same year car.

I am thinking that since the relay is on the Central Electronic Module (CEM), it needs to be fixed or replaced, but want to confirm.

Another question is, if I replace the CEM, do I need to reprogram the car with the dealer software???? The CEM is expensive, but not terrible used.... But the dealer would likely double the cost to fix.

 

This guy had the same problem. Voltage present.

Seems it is the CEM. He plugged in a new one and it worked without VADIS dealer software, so I think I will try it. I report back in a week or 2.


2000 V40 headlight issue - Troubleshooting and DIYs - 30 Forty 50

 

I had exact same problem. Cost me $8 plus some soldering to fix.
I used this relays
GENERAL PURPOSE 12-VOLT D.C. 12-AMP SPDT RELAY
ordered at frys (Radio Shack was out of them)

FRYS.com | NTE

replaced couple which control left and right low beams. You will need good desoldering/soldering equipment.

Good luck!

 

Thanks,

Already ordered a used CEM.

Interestingly, I had the same idea and also ordered a relay from mouser electronics that seemed to be the closest part number to the relay that is on the CEM (which is no longer available). Had no idea these are available in Radio Shack or were pinned the same way.... I ordered the closest part # in hopes the pins would match up, but seems these relays are standardized? I had no idea....

This is what I have on order. It turned out to be wrong.... The one above I did order, put in and it worked.

817-FTR-P5CN012W1 - WRONG!!!!

I'll put the new CEM in, and then play with the old one.

I have not played with circuit boards before, so this will be a new one for me. Thank goodness for youtube.com for instruction! I feel I have a good chance of success after watching, and getting the feel for what is involved. I may have to dig around for a circuit board to practice on though.

I have a question though... I see all sorts of "Desoldering pumps" and "Solder Suckers"... What is "good desoldering equipment"? I see many cheap desoldering pumps, are these good enough? Or is there a reasonably priced desoldering pump that I should use? Or is the ebay under $5 pump good enough, (or the $10 made in Germany one a better choice?).

 

Hi,
I use inexpensive desoldering iron, one from Radio Shack
RadioShack® 45-Watt Desoldering Iron - RadioShack.com

This is not a finest circuit, anything with some sort of pump should work.

My real concern is that I do not really see any damage to the old relays. Something else must be causing it fail to switch. Could be bad grounding. But my prime suspect is the headlight assembly itself. It is mostly plastic and most of the plastic is already broken or about to break. All electrical contacts are shaky and vibration could cause the circuit to break. I will replace that as soon as I can.

 

Replaced the CEM and light is back on. No VADIS reprogramming needed.

Just, if you disconnect the battery like I did, remember to have the radio code on hand to turn the radio back on.

I should have mentioned that this light had failed before, due to a melted terminal on the bulb. I spliced in a new one about a year ago, and it has not overheated since. The light fixture did rattle a bit due to a leveling gear that had come off the rod that it is supposed to turn. I glued that back so the rattle would not happen.

I have no idea what can cause a relay to fail. I thought that once it got the signal to turn on the juice, it would just do that (if it were not broken) and fuses would protect against shorts and the like. I suppose if the relay did not have a good ground, it could not do it's job? Or, it the ground used by the light was not good, the circuit could not be completed...

 

How on earth did you split the CEM case???? Just spent the worst half hour of my life trying.

 

I did split the case. There was a philips screw located underneath the ID number decal.