Headlight problem

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eujinee

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Guys,I've a problem with left side headlight....everytime i start engine..it turn "ON"...not the small bulb..but its the main head lamp...it turn ON only 1 side when i start engine..and..wen i off..i remain "ON"..even off my engine it still remain "ON"...i tried on off several times only manage to turn it off..but everytime i start my engine again..i turn back on...forcing me to disconnect the bulb...have any body experience the same problem..mine car is pre facelift m43b19.....please advise..
 
Hi eujinee,

hope I can squeak my thoughts and advice eventhough never experience the same problem. You mentioned that you managed to turn it off after cycling on-off a few times, it sounds like something is wrong with the light switch relay where it got stuck. My suggestion is rip the light switch out and check out the relay inside it.
 
aidilj;689416 said:
Hi eujinee,

hope I can squeak my thoughts and advice eventhough never experience the same problem. You mentioned that you managed to turn it off after cycling on-off a few times, it sounds like something is wrong with the light switch relay where it got stuck. My suggestion is rip the light switch out and check out the relay inside it.

thanks....i was thinking of a sticky relay too..but our headlight is connected to a control unit...i diy a solution taking right headlight wire connected to left on operation...simple but it works...
 
eujinee;690627 said:
thanks....i was thinking of a sticky relay too..but our headlight is connected to a control unit...i diy a solution taking right headlight wire connected to left on operation...simple but it works...

Won't that trigger a faulty light dash warning?
 
yup it will....system is running close loop config...will try and figure out how to solve tht...my opinion is the working unit parallel with the faulty headlight...the faulty wiring open loop will try to wired into the close loop to disable the dash warning...
 
I was just thinking, if the switches are all solid state then you wouldn't be able to turn it off at all.. Let me check wds.
 
It seems the only switch would be in the LSZ area, to check if there is relay try to activate follow me home function and listen for clicking at the switch.

lsz.png


lo_beam.png


Light switch centre (LSZ)

In addition to the electronic control and monitoring system for the external vehicle lights, the light switch centre also comprises the switch for sidelights/dipped beam, the pushbuttons for fog lights and rear fog lights as well as the potentiometers for instrument locator lighting and manual headlight vertical aim control.

Scope of functions of light switching centre

•Control and monitoring of the outer headlights and lamps, including the indicator and hazard warning flasher function
•Control of relay for fog lights
•Evaluation of load sensors for automatic headlight vertical aim control and the resulting activation of stepper motors of evaluation of potentiometer for manual headlight vertical aim control.
•Dimmer function for instrument and locator lighting (terminal 58g) as well as the function and locator lighting for the hazard warning switch.

Communication with other control units and diagnosis takes place via the K-bus. The light switching centre receives information via this bus relating to the vehicle status and also provides information on the status of the controlled lamps (defective/OK, switched ON/OFF).

The indicator lamps for full beam, fog light, rear fog light and direction indicators in the instrument cluster are controlled by the light switching centre on the basis of K-bus telegrams.

Design

The light switch centre consists of a control unit and operating panel


Both units are interconnected by means of a plug connector.

Control unit

The control electronics is accommodated in the control unit.

Operating panel

The switches for sidelights/dipped beam, fog lights/rear fog lights as well as the dimmer for headlight vertical aim control and instrument lighting are integrated in the operating panel.

The operating panel can be replaced separately from the control unit.

If replacement is necessary, corresponding reference to this is made in the test module.

Lamp monitoring

The lamps are monitored in OFF and ON status.

Cold monitoring in the OFF status takes place by briefly switching on the lamp (so short that the lamp does not light up). The lamp current is monitored and an assessment is made as to whether the lamp is defective or not.

Note

If the battery voltage drops below approx. 9.5 V, the lamp status can no longer be monitored or output.

Activating indicator lamps in the instrument cluster

The indicator lamps for left direction indicator, right direction indicator, rear fog lights, fog lights, full beam as well as the LEDs in the pictogram incorporated in the instrument cluster are activated via the K-bus.

Emergency mode

Independent hardware is provided in order to maintain the functions necessary for driving safety in the event of the control unit failing.

If the light switching centre is in emergency mode,
•Tail lights and dipped beam lights are switched on at terminal 15 irrespective of the position of the corresponding light switch
•Left and right brake lights are switched on at terminal 15 and the brake light switch operated
•Direction indicators, hazard warning lights, full beam, headlight flasher, fog lights and rear fog lights cannot be switched on.
•Diagnosis is not possible

If in emergency mode, the light switching centre must be replaced.


from : http://wds.spaghetticoder.org/en/zinfo/FOI0398FB-046613101.htm
 
arrhhh...finally..been looking for schematics for this....thanks bro......will figure it out soon enuf...
 
aidilj;690684 said:
I was just thinking, if the switches are all solid state then you wouldn't be able to turn it off at all.. Let me check wds.

the DIY king has spoken :listen::top:
 
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