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Another pesky Prius 2 headlight problem

Discussion in 'Gen 2 Prius Technical Discussion' started by ze_shark, Jun 4, 2017.

  1. ze_shark

    ze_shark Junior Member

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    2008 Prius 2, first owner, 50Kmi.
    The car has developped an intermittent problem with the driver side headlight. Turns on fine, but turns off after about 30 seconds. Turns back on if the lights are toggled off/on. Sometimes took a couple of retries on the light switch to "fully" turn on.

    First, the bulb got changed by the dealer at their own initiative at the occasion of an oil change. Different bulb model, clearly warmer temperature, but problem still present.

    Then I decided to go after the ballast. Ordered a replacement ballast, followed a DIY to take the headlamp module out, swapped the ballast with the new one, remounted, everything seemed fine. For a few days at least.

    Now the headlight turns off again after 30s. Observing the symptom closer:
    - when cold (first attempts), the light flickers several times and fails to turn on


    - after a few tries, the light stays on 30s, then flickers before going off


    - if I toggle the headlight switch, it goes back on, etc ...

    Passenger side running fine. Original ballast and bulb. No problem.

    My next move in consideration is to swap the bulbs to see if the bulb+ballast combination is marginal, and the OEM bulb will run fine with the new ballast, while *maybe* the new bulb runs fine too on the OEM ballast (or I can limit further actions to finding another colder D2R bulb).

    Before I go through the joy of swapping the bulbs, I would like to know whether there are possible other upstream root causes i am ignoring.

    I don't see how the ECU could be responsible. If i understand the schematics correctly, the relay toggles the power that goes to both headlights, so the problem can't be there.
    Could a brand new ballast be defective ?
    Could the warmer D2R bulb installed by the dealer be incompatible with the ballast ?

    Many thanks in advance for advice or insights. This car has been really reliable, but this problem is a safety concern.
     
  2. ze_shark

    ze_shark Junior Member

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    So i have done my bulb swap:
    - side which works, OEM bulb: OSRAM Xenarc D4R 66450
    - side which does not work: Philips D4R XenEco 42406

    After swapping, the problem follows the Philips D4R, so that bulb is not compatible with the OEM ballast.
    Ordering a replacement OSRAM bulb.
     
  3. TMR-JWAP

    TMR-JWAP Senior Member

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    Your bulbs seem to be confused. The OEM replacement should be a Philips D4R for all 2006-2009 with HID. My understanding is that a D2R should never be installed in place of the D4R, as it isn't compatable with the ballast and may cause damage. D2Rs were used in the 2005 only.
    Authentic Philips D4R bulbs are available online from HomeDepot for about $50 each. AUTHENTIC, not amazon off-shore impersonators.
     
  4. ze_shark

    ze_shark Junior Member

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    I wrote D2R in my first post by mistake, I have D4Rs.
    But the fact is that, on this 2008:
    - OSRAM Xenarc is/was OEM
    - the replacement Philips Xeneco my dealer installed challenge the ballasts, both original and replacement, to the point of malfunction.
     
  5. pashko90

    pashko90 Junior Member

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    Seems like ballast problem for me. Just my .05
     
  6. TMR-JWAP

    TMR-JWAP Senior Member

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    the problem follows the Philips D4R, so that bulb is not compatible with the OEM ballast.

    I don't know that I would go as far as saying the bulb is not compatible with the OEM ballast. Apparently, the bulb isn't functioning correctly in your vehicle, but hundreds of thousands (millions?) have worked perfectly fine in a bunch of other 2006-2009 Prii. I would be more inclined to say there is something specific to your car, bulb, ballast, wiring, etc that is a contributing factor.

    Also, are those headlights original? They look better and more clear than any gen 2 (or any other 9 year old car) I've ever seen.

    Please let us know how the repair goes.
     
  7. ze_shark

    ze_shark Junior Member

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    Yes, the headlights are OEM, nothing's been changed, and it shows no haze at all. Car is bone stock. Surely gets less sun than if it was parked outside in a warm climate.

    I will have to differ with you on the bulb:
    1) the driver side ballast is brand new. It works fine with the OSRAM Xenarc, but doest not work repeatably with a 2m old Philps Xeneco
    2) the passenger side ballast is original (2008). It works fine with the OSRAM Xenarc, but does not work at all with the Philips.
    3) OSRAM Xenarc is the original equipment, not Philips (in this car)
    4) the Philips Xeneco has a completely different temperature and far lower intensity than OSRAM

    Admittedly, I am just looking for a solution since I am sellling the car anyway, and yes, that Philips bulb, though 2m old in its 150$ glory, could be marginally defective, have excessive impedance. I am not too sure what else could have an influence. Control signal drives the ballast, ballast drives the bulb.

    I just got a 2nd OSRAM Xenarc so I'll be able to confirm my observations and deliver the car.
     
  8. ze_shark

    ze_shark Junior Member

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    OSRAM Xenarc swapped in and everything back to normal.
    So on this car and FWIW, Phlips Xeneco can challenge an OEM ballast, old or brand new.
     
    SFO likes this.
  9. Beachbummm

    Beachbummm Senior Member

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    any update?
    going to change to halogen if the problems continue on the 08 with the HID's
    but if its the bulbs Ill give it a shot..