Headlights & LWR

[helloitsme]

Hello,

I recently discovered that my pre-facelift E85 (2003) was originally equipped with bi-xenon headlights. However, the current aftermarket Sonar headlights installed on the car are halogen.

I’m getting an error code in INPA every time I turn on the headlights without the engine running. When the engine is on, the code doesn’t appear. The error comes from the LSZ module and is code 34 – front LWR short circuit to ground.

I’ve already replaced the front ride height (load) sensor, but nothing changed.

Interestingly, the headlights still perform the tilt self-test at startup. But I don’t think they are actually communicating with the load sensor. When I checked the LSZ coding in NCS Dummy, both manual LWR control and automatic LWR control were active. When I disable manual LWR control, the tilt self-test at startup stops.

Since the car originally had xenons, there’s no manual headlight leveling wheel inside the cabin.

Does anyone have an idea what to try next? Ideally, I’d like to car do the correct tilting / autoleveling for the headlights.

Thanks in advance!

 

[enuff_zed]

Not sure it'll solve your issue but don't forget there is a level sensor on the rear right as well. Easily broken if new springs are installed.

 

[helloitsme]

Yes i know, but the inpa error says “front load sensor”.. but i think sensors are not the problem, but compatibility with headlights..

 

[Scooba_Steve]

Does anyone have an idea what to try next? Ideally, I’d like to car do the correct tilting / autoleveling for the headlights.

I don't think that will be possible.

Interestingly, the headlights still perform the tilt self-test at startup.

I also don't think that's what it is. The halogens do it too iirc.

 

[helloitsme]

Can anybody tell me if the smaller 4-pin connector on the headlight or harness (with blue, green, yellow, and white wires) is for the leveling motors? I mean, there’s one large 8-pin connector, and then there’s this smaller one

 

[r3vmatch]

Can you post a screen shot from NCS dummy disabling manual light level control? The "bzzzzt" when the headlights comes on really annoys me and I would love to stop it.

Regarding debugging your issue, when I first got my Z4 and the Xenons did the self-test on-start-up with the associated "bzzt" I thought there was something wrong so I played with the front level sensor. I disconnected it from the control arm by removing the nut (8mm?) and I manually rotated the sensor. When I did it SLOWLY (like < 0.5 Hz) I could hear the headlights change their level and when I used a mirror I could see them move up / down. I didn't mess with the sensor on the rear end. When I moved the sensor REALLY fast the headlights didn't really adjust their level, which makes sense, if you're hitting a bump ('fast sensor change') the car doesn't want to reposition the lights but if you're going up an incline or dealing with a decline, that's more slowly moving.

Though it might be annoying to get under the car to mess with the sensor (again), you could try this.

One other comment, since you changed the sensor and there was no difference and the errror is "short circuit" maybe the issue is with the wiring loom, possible a rodent or something has chewed the insulation? That happened to me on one of the wires going to the starter. I don't know if the sensor speaks to the car body using CAN-bus, but if so you could also use a multi-meter between the CAN_L and CAN_H , there's supposed to be a resistor across the pair (for signal termination) probably ~120 ohms, but you shouldn't read a SHORT circuit.

I'm also attaching some information on how the LWR system works, this is for E46 which should apply to the Z4 and a file that describe the subsystems/communications system used in the Z4 between modules.

 

[r3vmatch]

I'm 90% certain the 4-pin wiring on the headlight is for the leveling motors -- the leveling motor also has four wires (it's a stepper motor). I have a spare Xenon headlight light on the bench and can test it in a day or two to confirm.

 

[r3vmatch]

Sorry for not collapsing my feedback in one post -- if I remember correctly ISTA-D ("Rhengold") had a diagnostics for the leveling sensors and it would show you in real-time what the sensor is telling the car. That might be an "easier" way rather than disconnecting the leveling sensor.

ISTA-D is also more sophisticated and has diagnostics tests including those to move the headlights up/down, etc.

 

[helloitsme]

Can you post a screen shot from NCS dummy disabling manual light level control? The "bzzzzt" when the headlights comes on really annoys me and I would love to stop it.

Regarding debugging your issue, when I first got my Z4 and the Xenons did the self-test on-start-up with the associated "bzzt" I thought there was something wrong so I played with the front level sensor. I disconnected it from the control arm by removing the nut (8mm?) and I manually rotated the sensor. When I did it SLOWLY (like < 0.5 Hz) I could hear the headlights change their level and when I used a mirror I could see them move up / down. I didn't mess with the sensor on the rear end. When I moved the sensor REALLY fast the headlights didn't really adjust their level, which makes sense, if you're hitting a bump ('fast sensor change') the car doesn't want to reposition the lights but if you're going up an incline or dealing with a decline, that's more slowly moving.

Though it might be annoying to get under the car to mess with the sensor (again), you could try this.

One other comment, since you changed the sensor and there was no difference and the errror is "short circuit" maybe the issue is with the wiring loom, possible a rodent or something has chewed the insulation? That happened to me on one of the wires going to the starter. I don't know if the sensor speaks to the car body using CAN-bus, but if so you could also use a multi-meter between the CAN_L and CAN_H , there's supposed to be a resistor across the pair (for signal termination) probably ~120 ohms, but you shouldn't read a SHORT circuit.

I'm also attaching some information on how the LWR system works, this is for E46 which should apply to the Z4 and a file that describe the subsystems/communications system used in the Z4 between modules.

Hello, Thanks for helping..
i didnt took the picture of ncs dummy, but in my case it was in ALSZ module, and theres whole section of settings for LWR, in my case this section was with light green background. Theres i think two important settings, LECHWEITENREG_AUTOM, which is automatic vertical headlight aim and the other one something like LECHWEITENREG_MANUAL, which should be AKTIV, for halogens headlights, as they do have manual wheeler in cabin.. i had activated both, even though i dont have the wheeler.. So i tried different options, and when i disactivated the manual one, lights didnt do the start up tilt “check”, just stayed in the position.. I dont know if it will be same in your case, you can try..

Edit: i found at least the photo of the Automatic one, the manual should be close to this one.

 

[helloitsme]

Sorry for not collapsing my feedback in one post -- if I remember correctly ISTA-D ("Rhengold") had a diagnostics for the leveling sensors and it would show you in real-time what the sensor is telling the car. That might be an "easier" way rather than disconnecting the leveling sensor.

ISTA-D is also more sophisticated and has diagnostics tests including those to move the headlights up/down, etc.

Thanks, i had a problem to find ISTA download link before, but i will try to look.. INPA have the lwr reading too, but its poor or maybe i dont understand it well.. but i tried to look for some commands to activate the motors moving, through inpa, to confirm if the headlights motors work with car, but i couldnt find that in INPA..

 

[r3vmatch]

Hi,

Thank you for the screenshots, I'll take a look at NCS Expert / Dummy when I have a minute.

I opened the spare Xenon headlight I have, removed the leveling motor and used a multi-meter to CONFIRM the 4-pin grey connector on the headlight housing connects directly to the leveling motor via a black connector that has four identically colored blue wires.

It's a 1:1 mapping between the outside connector and the inside connector:

Grey.PIN1 <--> MotorConn.PIN1
Grey.PIN2 <--> MotorConn.PIN2
Grey.PIN3 <--> MotorConn.PIN3
Grey.PIN4 <--> MotorConn.PIN4

I'll follow-up (probably tomorrow) with screenshots from Rheingold/ISTA-D displaying what I see when I run the headlight leveling tests on my car, what it shows for the leveling sensor, etc.

Here's pictures of the grey connector (outside, headlight housing) and the black connector that goes to the leveling motor: