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I took my 07 Prius to the shop three times while under warranty to get the headlights adjusted. I thought they just did a mechanical adjustment. Then I read today about a sensor that is supposed to do this automatically. Does the 07 have this sensor? I don't know what the Toyota warranty people did, but they never said anything about replacing a sensor. The lights are out of adjustment again - on-coming cars flash at me when the low beam lights are on.

Thanks,

Steve

Hi, stevesprius,

All the Priuses from 2004 through 2009 have a sensor for the automatic headlight leveling system ONLY if you have HID (High Intensity Discharge) headlighhts. The easy way to tell if your headlights are HID's (& NOT halogens) is to look at the lower grill in the front. If you see the round fog lights in the lower grill, then you have HID's & will have the sensor attached between the rear axle on the left side of the car & the floorpan. This sensor can get corroded inside & NOT send the correct signal to the headlight adjusting motors to tilt the headlights back down when additional weight is added in the rear passenger compartment or in the cargo area (which would have raised the nose of the car, aiming the very bright HID's into the eyes of oncoming drivers & blinding them).

If you do have the HID's & you suspect you have a sensor problem, you won't always get any kind of warning light or message to alert you (I never did when mine quit at 13,000 miles), but usually the result is that you can only see about 20 feet in front of you with the lowbeams on. An easy test for you to do is to pull up about 20 to 30 feet away from a verticle surface such as a wall or your garage door & turn on your headlights & open your rear hatch. Now you or a family member kneel inside the rear gargo area & watch what happens to the light pattern on the verticle surface. The light pattern should move upwards initially, but after a few seconds should come back down to their original position. When you get back out of the car's rear, you should see the lights first tip down as the car's nose drops then they should re-correct upwards in a few seconds.

If you don't see any correction happening then you have a bad sensor & it will run between $270 to $300+ just for the part, then there is the labor charge to install it. You can probably do it yourself in about 10 to 15 minutes (I think only 4 bolts & a wiring harness connector), but if your car is still under warranty then get the dealer to put in a new one for you (there was a TSB for this) & make sure you see the package your new sensor comes in (because the part number must have a suffix letter "G" after the number (that's the new & improved one). If you're out of warranty & the sensor is the problem, then the dealer should still have to do the part replacement & the calibration adjustment mentioned in the TSB for free because you brought it to them while it was under warranty & they didn't fix the problem correctly yet.

Later on if you have the sensor problem again, either try to repair your own sensor as some here have done (do a search for "headlight sensor" or "headlight sensor fixed" to find step-by-step photos & directions of how one of our members fixed his. Somebody told us his dealer wanted to charge for 2.5 hours of labor just to install a new part (& maybe the calibration adjustment), but he was able to remove, repair, & re-install his in less than an hour. I hope this has been of some help to you.

See this thread, and download the PDF file in one of the posts:

http://priuschat.com/forums/gen-ii-prius-care-maintenance-troubleshooting/45884-headlight-level-sensor-corroded.html