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Replacing Your Headlight Switch

Pelican Technical Article:

Replacing Your Headlight Switch

Nick Czerula


1 hour1 hr






Plastic prying tool, Phillips screwdriver

Applicable Models:

BMW E46 3-Series (1999-06)

Parts Required:

Headlight switch, Lighting control module

Hot Tip:

A failing switch may cause the headlamps to flicker when going over bumps

Performance Gain:

Proper light function

Complementary Modification:

Replace headlamp bulbs

The BMW E46 headlight switch is part of the lighting control module or light switch center (LSZ). LSZ integrates a number of functions and features above and beyond switching the headlights on and off:

  • Main switch for headlights, taillights and running lights
  • Automatic headlight control if equipped
  • Foglight switch
  • Instrument dimmer control
  • Light control module
  • Monitoring of exterior lights while on or off (hot and cold)
  • Emergency lighting
  • Short-circuit protection
  • Service data and vehicle mileage stored redundantly (1999-2001)
  • Automatic headlight adjustment (LWR) if equipped with adaptive headlights

In addition, models equipped with automatic headlight control have a rain / light sensor (RLS) that turns driving lights and wipers on and off depending on ambient light and rain conditions.

The E46 headlight switch is mounted in the dashboard on the left side of the steering wheel. The switch fails over time and causes exterior lighting problems. The headlight switch is mounted to the lighting control module. When removed, they come out as a unit and can be separated and serviced individually. The headlight switch is not a big deal. You can swap them out without any special tools or software. 

If you suspect your lighting control module is faulty, you can replace it but new ones have to be coded with a BMW scan tool and can only be coded once. This means you cannot use a used part. However, you can swap your faulty one with a used one to be sure that is the problem. Once swapped out, the problem may go away. You will notice the tamper light in the instrument panel will come ON. It will go out as soon as you remove the part you were testing with. It does this because the VIN (vehicle identification number) is stored in the module. So buddy up with a local BMW shop and have them code the new module once you replace it.

In this article, I will go over the steps involved with replacing the headlight switch and separating it from the lighting control module in E46 models. 

Keep in mind that when your car was serviced before, parts may have been replaced with different size fasteners used in the replacement. The sizes of the nuts and bolts we give may be different from what you have, so be prepared with different size sockets and wrenches. 

Protect your eyes, hands and body from fluids, dust and debris while working on your vehicle. If you are working with the electrical system, disconnect the battery before beginning. Always catch fluids in appropriate containers and properly dispose of any fluid waste. Recycle parts, packaging and fluids when possible. Do not work on your vehicle if you feel the task is beyond your ability. 

Vehicle models change and evolve as they grow older, so the vehicle shown in our illustrations may vary slightly from yours. If something seems different, let us know and share your info to help other users. Do you have questions or want to add to the article? Leave a comment below. When leaving a comment, please leave your vehicle information.

Using a plastic prying tool, lever out the left side dashboard trim piece.
Figure 1

Using a plastic prying tool, lever out the left side dashboard trim piece.

Remove two the Phillips-head screws from the headlight switch (green arrows).
Figure 2

Remove two the Phillips-head screws from the headlight switch (green arrows).

Next, slowly pull the headlight switch out of the dashboard.
Figure 3

Next, slowly pull the headlight switch out of the dashboard.

With the headlight switch removed from the dashboard, unplug the electrical connector by pressing the locking tab and rotating the lever up (green arrow).
Figure 4

With the headlight switch removed from the dashboard, unplug the electrical connector by pressing the locking tab and rotating the lever up (green arrow).

To separate the headlight switch from the lighting control module, press the tabs to release the locks and pull it apart.
Figure 5

To separate the headlight switch from the lighting control module, press the tabs to release the locks and pull it apart.

Then pull the electrical connector off the headlight switch.
Figure 6

Then pull the electrical connector off the headlight switch. You may have to wiggle it back and forth slowly to remove it.

To install new the headlight switch, connect the lighting control module electrical connector to new the headlight switch. Then, clip the headlight switch and the lighting control module together. Connect the electrical connector and slide it into the dashboard. Then install the fasteners and install the dashboard trim piece.

Comments and Suggestions:
benner Comments: I have testet the cabel. There was the eror.
December 15, 2017
  Followup from the Pelican Staff: Thanks for the follow up. We appreciate it.
- Nick at Pelican Parts
Randy Comments: I have a 2004 325xi wagon. The brake lights stay on. Also have the warning on the cluster that shows the three brake light fault. Replaced the brake switch. Trying to chase this fault. Thinking it might be the control unit. Can the original unit be tested or I plug the unit to see if the lights go out?..
December 12, 2017
  Followup from the Pelican Staff: You'll want to test the signal from the brake light switch to the lighting module. if it is not commanded on, and the output is ON, the module may be faulty. - Nick at Pelican Parts  
benner Comments: Have a BMW 323CI from 2000. In the left rear double bulp taillight and brakelight, the taillight part of the bulp does not work. The brake part of the bulp does.
In the dashboard in the car, the red icon lights up and shows a fault on the left tail light.
Got the car tested by an autoelectrics who found out that the LCM did not deliver power to the part of the bulb that does not work
Replaced LCM with a used LCM
After replacing, the taillight still did not work and the red icon still showed that the left tail light has a fault.
Can the error be in LCM or may it be a cable error?
December 12, 2017
  Followup from the Pelican Staff: I would run a test wire from the module to the bulb holder, does this fix the issue? - Nick at Pelican Parts  
Blake Guski Comments: What are you suggesting the issue is if the wire is cut and the voltage returns to normal?

Trying to get all the info I can before cutting into my harness.
November 30, 2017
  Followup from the Pelican Staff: It is a test to determine where the voltage loss is. - Nick at Pelican Parts  
Blake Guski Comments: Hi. I have replaced my whole module 3 times now. Same result keeps happening.

Passenger low beam works, high doesn't.
Driver high works, low doesn't.

Front driver turn signal works, rear doesn't.
Rear passenger turn signal works, front doesn't.

I checked voltage at the driver low beam and it's abo it 4.95v
Any ideas?
November 28, 2017
  Followup from the Pelican Staff: Go to the module, is voltage 4.95 also? If so, cut the wire at the module, does voltage on the module side return to normal voltage output? - Nick at Pelican Parts  
Frustrated E46 owner Comments: rying to troubleshoot my problem. my passenger side light went out after car wash, and I found the ballast had water in it. I removed it dried with a hair dryer and it worked fine. replaced the headlamp and then the driver side stopping working. I figured ame problem, except I swapped every piece xenon bulb, inginter, ballast even the adaptive controllerS from side to side with having the same issue with the drivers side. I even heat shrinked the tiny 20 gauge wires that insulation flaking off of them. Before I understood the lcm would rest if you pulled it out, I sent a used lcm and had it re programmed for vin/mileage, and that worked great. However, I still have to pull the lcm out to reset it after each time i drive. My drivers side headlight is always the culprit, i v'e switched ballasts, igniters and even adaptive modules from side to side, every time the light comes on after resetting the lcm. I can drive for a half hour plus with both lights working. But after i turn off the car, remove the key , and try to use the headlights again the drivers side will not work without removing and allowing the lcm to reset. It's driving me crazy, I really hate this car Sadly it only has 64k on it.
November 15, 2017
  Followup from the Pelican Staff: Are any fault coders stored? I would assume the issue is wiring if everything else has been replaced. - Nick at Pelican Parts  
NormanBMW Comments: Greetings!! I have a 2003 325xi wagon and the tail lights are SO dim it barely illuminates at night. Wondering if it is the lighting control module. Checked the ground and that isn't the problem.
September 26, 2017
  Followup from the Pelican Staff: If voltage is low to the bulbs, the LCM can be at fault. - Nick at Pelican Parts  
axl vader Comments: i had problems not turn on with the headlight on both sides on a bmw 2003 , 330 xi, i change the control light, it didn't fix it, i check the power light wire from the control light to the bulb connector and is good, i was wonder do i need to reprogram the light control for this year model ?
August 20, 2017
  Followup from the Pelican Staff: if you have power, it is possible the ground to the bulb is faulty. - Nick at Pelican Parts  
kurt Comments: I have a 2006 325ci with turn signal issues. They will randomly not turn on or will not turn off.Lever returns normally but lights stay on. Replaced the multifunction switch worked good but problem returned. Reinstalled original MF switch worked ok but problem eventually returned. Thinking must be the lighting control module. Any thoughts? Thankyou
April 3, 2017
  Followup from the Pelican Staff: I think you're on the right path, make sure to check the faults in the module before replacement in case you have an intermittent communication fault which disrupts the signal from the MF switch. - Casey at Pelican Parts  
Tony Comments: I've got 04 325i and the high beams bulbs flicker for no reason. I unplugged the bulbs and realized the HID driving head lights flicker also. Thinking signal switch
March 9, 2017
  Followup from the Pelican Staff: I would check the grounds to the bulbs. if ok, monitor control power to the high beams to see if it is changing. DO NOT test voltage at the HID lights. The voltage is too high to test and injury can occur. - Nick at Pelican Parts  
Mike Comments: I have just purchased a 2001 325xi sedan. I have a headlight problem. My low beams, driving lights and brake lights seem to work just fine. I have no high beams or high beam indicator. I can't tell if any of the dash lights indicating a bad bulb are working. I am wondering if my light control module is defective. Would a fault code show up when diagnosis from a BMW shop? I just had to replace the right/ passenger headlight assembly due to the high beam socket. It was melted. The shop claimed it was probably a bulb misinstalled and caused arching and therefore heat. The shop claimed I needed to replace the assembly before a fault code would show up. Would any personal hand held scan tool work for diagnosing and coding a situation like this for a DIYer?
July 30, 2016
  Followup from the Pelican Staff: You would need an advanced BMW scan tool to read faults. There may be a fault for the high beam circuit, if the module can see something is wrong.

The melted connector can be due to a faulty ground or incorrect bulb.

i would check the high beam switch signal from the steering wheel stalk to the LCM.
- Nick at Pelican Parts
kevin Comments: thank you.
December 2, 2015
  Followup from the Pelican Staff: you're welcome. - Nick at Pelican Parts  
kevin Comments: i have 2005 325i and my flashers turn on by them selves. i have removed the hazard light/door lock switch completely. and the flashers are still turning on randomly..any idea what this could be?
November 27, 2015
  Followup from the Pelican Staff: I would assume this is an issue with the lighting control module. I would start by checking the vehicle for fault codes. If the system is not working properly, a fault code will be set. This will be your best bet when diagnosing.
- Nick at Pelican Parts

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Page last updated: Sun 2/18/2018 02:25:57 AM