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lexpert, Lexus Master tech
Category: Lexus
Satisfied Customers: 9974
Experience:  Master Certified with lexus, 8 years experience with Lexus
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2006 lexus GS300. Passenger side HID low beam goes out on occasion

Resolved Question:

2006 lexus GS300. Passenger side HID low beam goes out on occasion (will stay on for awhile if I turn lights on/off again). Replaced bulb and still have problem. Dealer recommends replacing entire headlight assembly (expensive). Seems that it could potentially be a ballast problem, which is much less expensive. Would you recommend replacing that (looks like around $100 for Denzo)? How easy to replace? What are the steps?
Submitted: 7 years ago.
Category: Lexus
Expert:  lexpert replied 7 years ago.


Hello and thank you for using just answer!

No I would NOT replace the entire headlamp here.

Switch the driver and passenger side bulbs here (careful not to touch them).

If the problem stays on this one side then the issue you have is the headlamp ECU that is inside the headlamp and this can be replaced seperately.

Customer: replied 7 years ago.
is that different from the ballast?
Expert:  lexpert replied 7 years ago.
Ballast is the term commonly used for the controllers on cheap aftermarket ad on HID's. Your car has a headlamp ECU built into the headlamp that fires and controls the hid bulb operation.
Customer: replied 7 years ago.
Thank you. A couple more things and i will accept...

Denso is a toyota-lexus partner and I see their "ballast" available. If i search headlight ECU there is only one and it is much more expensive, and no picture. Do you think the ballast is the ECU?

How easy to replace?
Expert:  lexpert replied 7 years ago.
if you give me your vin# XXXXX can give you the correct part # XXXXX the ECU if you are trying to cross refrence something on it......
lexpert and 2 other Lexus Specialists are ready to help you
Customer: replied 7 years ago.
i need to leave and pick up my daughter. can i get back to you later. thanks. i will accept this, but will need to get that info to you tonight.
Expert:  lexpert replied 7 years ago.
It's nearing 11pm in my time zone.....I am mostly online in the evenings, if you can reply back to me when you can I will check that for you first thing tomorrow when I get back online and relay the information you need then.....your "accept" does NOT lock you out from us still sending replies here now.
Customer: replied 7 years ago.

Here is the link to the Denso part I was referring to...

Expert:  lexpert replied 7 years ago.

ok, what sucks here is While the headlamp ECU is a seperate part it does not show this as available to purchase seperately now......they make you purchase the entire headlamp, they initially offered all parts of these lamps seperately when this car was first released to keep warranty costs down, looks like they have changed this now that the car is 5 years old.

I can tell you that the headlamp ecu that you linked me to on ebay is a SCAM, if you look closely at the pictures you will see that while it appears to be 2 different angles of the same part this is actually 2 different parts.....neither of which are good part #'s in the Lexus parts database I am looking at here. (I have access to the FACTORY parts catalog)

What I would recommend here if you want to keep costs down is to purchase a used headlamp assembly that you can pull the ecu out of rather then installing a questionable one.

I would still swap the 2 bulbs as I originally stated to be sure this is not a bulb issue.