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Left Main beam not working, but the bulb is fine...
I just got the message in my display, that the left side main beam is burnt. I checked the bulb, but it is fine. It is also working when plugged in on the right side. The bulb is a H7 type. And my lights are the BiXenon types.
Any ideas? Could it be a problem with the light switch? I had to work around its back side today, because the height adustment of my steering wheel is broken. Bu I can't see any problems there. Could someone maybe point me to the schematics?
I did quite some digging on my own, but I really don't understand quite yet how that whole lighting system works.
So the first thing I found out is, that the bixenon lamps do in fact have one xenon bulb and one h7 halogen bulb. The xenon bulb is used for normal lighting and high beem. The h7 "assists" the high beam. There is a electronically actuated flap in front of the xenon bulb that is lowered for the high beam.
In my car, the h7 on the left side does not come on while the flap in front of the Xenon is also not working. In my dash, it says my left main beam is not working. It is the same message one would get with a blown bulb.
The SD has several faults active in the left LWR Module (Partnumber A2038201685, I think this is the module in the left lamp itself):
Sorry, it's in german. It basically says that my height adjustment is not working and the ride level sensors are giving nonplausible data. Witch is very wired. Because my car has ABC, so the lamps are fixed and don't have automatic height adjustment.
Not sure if the not working high beam is related to this. But those faults are stored for the left side, too.
The lights are switched by the driver side SAM N10/10. But I could not figure out yet how the communication works here.
Also I am thinking that maybe there is some kind of programming error. Or even the SAM might be bad.
The car is new to me and I had a bad voltage regulator blowing up my rear battery a few days ago. So I do not know what the previous owner did to this car. And I also do not know what kind of damage the overvoltage might have caused.
Your car has front and left headlamp range adjustment. You have a fault for your left-front level sensor (B22/8). Though this is wired to the ABC controller and used by the suspension, it is also used by the range adjustment.
I think the module "LWR-VL" is synonymous with driver-side SAM.
By the way, if you double-click on any fault, Star Diagnosis will guide you through a sequence of troubleshooting steps to assist you in locating the source of the fault.
No, I don't have range adjustment.I checked the part numbers on the headlamps. They are both BiXenon units without height (range?) adjustment as per part number and actually looking at them.
The LWR-VL is a german acronym for "range adjustmentmodule front left" (LeuchtWeitenRegulierung VornRechts). In the short test results list it is showing the part number of that module as A2038201685. This is a module that is part of the headlamp. When I did a search online, the vendors state that this part is campatible to basically all SLs, with or without ABC. But only the models without ABC have a range adjustment, because in cars with ABC, the ABC ist taking care of that by leveling out the car. I conclude that there has to be some menu to configure the lights beeing a non range adjust version. Or the car beeing ABC-equipped.
I my car, the sensors B22 (there are 4 of them) are "connected" to the ABC-Module. If those were faulty, the ABC would be complaining about them. (Or so I think.) But it is not.
The first line error code states that the lamp was not able to clibrate. No wonder.
The last line complains about the range adjustment motor beeing faulty. Again. No wonder as it isn't even there.
So in this case, the trouble shooting guide isn't of much help, sadly.
Because my car has ABC, so the lamps...don't have automatic height adjustment.
I did not know this. And to think of all of the Quick Tests I've run over the years and do not recall ever noticing that the "HRA" modules are not present.
In my software (same release date as yours) there are only a dozen or so possible faults that can exist. None of the three you have are on that list, but they are on the list for the SAM. So there is an odd inconsistency between our softwares, it seems. And it's bizarre to me that you can "connect" to a module that does not exist.
I suppose you've checked the SAMs for faults. That is where your headlamp issue would surely register with my software.
As you can see in the following picture, the SAMs tested out fine:
If I understand that correctly, the HRA is the english version of LWR, right? I think those modules are in fact always present. But they maybe change their behaviour depending on the presence of ABC.
I did read a few posts about the SAMs causing one headlight not working. But in those cases it was the xenon failing, sometimes intermittently. But in those threads they said, that the SD had flaged one of the SAMs as faulty...
I really suggest you set your das to english if you want people to understand your screens
if you can't change it in the interface,
change your shortcut to \DAS\bin\das32r2_slt.exe" -len
If I understand that correctly, the HRA is the english version of LWR, right?
Yes, that's correct.
Earlier I think you wrote something about HRA being integrated into each lighting unit. That is indeed the case, and HRA is synonymous with headlamp control unit.
Since you have a non-working headlamp, you should see a fault in your LWR (HRA) module. But you do not. And as I stated earlier, the faults you do have do not exist for the LWR in my software, but they do for the SAM. I note that I am looking at Sim DAS, and while I believe I've seen slight differences with the simulation version, I certainly haven't seen anything as dramatic as what we have here, Matthias.
I just was at my car and did some more fiddling with the DAS.
I did the short test once again. It now shows the faulty main beam in the driver side sam menu. (Not in the HRA menu!)
And, going to the HRA-menu again, I found a submenu called (something like) "reading the coding". Klicking on that, it told me that the currenty stored parameter set in the HRA was wrong. It was "W203(Code803), S203(Code 803)" but it should be R230. It asked about writing the correct parameter set and warned, that both left and right modules would be written to. Of course I said yes. And of cours it failed with the error message "communication error 8.568.0". Ah well.
It semms that DAS was able to write *something* into that lamp module, als it now thinks, it has the correct R230 parameter set. But it all did not change anything regarding the behaviour of the lamp. It still thinks it has range adjust. And the high beam still doesn't work.
One more funny thing happened. I had my cheap chinese radio running while I was playing with DAS. At one point I tried shutting the radio off, so I could hear the high beam shutter klicking, while I was turning the lamps on and off individually. Instead of turning the radio off, I switched the source to AUX. And then I realized, that switching on the left high beam caused the radio to "play" a faint "bjuuuu"-sound. Strange. The right high beam did not cause any sound. (Of course switching the left high beam on and off in DAS did not actually turn on the lights. It just caused the sound.)
I really suggest you set your das to english if you want people to understand your screens
if you can't change it in the interface,
change your shortcut to \DAS\bin\das32r2_slt.exe" -len
I went and measured the pins on both head laps There are two connectors, but the small 2pin connectors have nothing to do with the high beam, so I did not measure them.
I did my measurements with the connector disconnected.
Pin 1 on the left is switching from 0 to 12V when the high beam ist switched on.
Pin 1 on the right is on 9,1V all the time and it twitches up for a split second with the high beam switched on. I think the module detects the missing bulb and switches off the current immediately.
Pins 4 and 6 are connected to,ground.
Pins 5 are at a constant 8,6V
Seeing the switching on Pin 1 of the left lamp I am leaning towards that lamp being defective. But why are there constantly 9 volts on pin 1 of the right lamp? So wired.
Found the error. Inside the lamp, the cables are crumbling. Or rather the insulation is crumbling from age and heat. There was a short on one of the wires leading to the high beam actuator. I bent the wires apart and the lamp works.
But now I have to take the lamp apart and rewire it completely. What a pain!
Found the error. Inside the lamp, the cables are crumbling. Or rather the insulation is crumbling from age and heat. There was a short on one of the wires leading to the high beam actuator. I bent the wires apart and the lamp works.
But now I have to take the lamp apart and rewire it completely. What a pain!
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