Litronic Headlight Aim off

[eben]

Hello all, I am new to this forum. I am getting lots of good info about my car that I have owned for about 8 months. Thanks.

Just returned home following ( and at times leading ) while my wife was driving my 02 C4S Coupe Manual. The car has daytime running lights ( Canada ). She has complained that previously when I followed her while I was driving the P car, that the drivers side headlight was very bright compared with the other. It almost looks as though the drivers side light is moving up and down slightly. She pulled over once because she thought I was flashing her.

When I had the car serviced last I asked for a check of the aim and operation and they said it checked out fine (and charged me extra for the check). When against the garage door, the pattern seems similar with the drivers side slightly higher than the passanger side.

The manual says that the lights should stroke when the key is turned on and they do but not by an equal amount. The drivers side makes the same noise but doesn't appear to move as much.

Is there a home garage quick check to see if something is not quite right with the mechanism?

Also, how is the attitude of the car sensed in order to adjust accordingly? Maybe I have a flaky sensor?

Any ideas or checks would be appreciated.

Eric

[Izzy]

Do you have the owner's manual? There is detail there on checking and aiming the headlights when they come out of alignment. If you don't have it, download it from this site, I believe the same instructions are there too.

I have daylight running lights in mine too (not from factory, but just by connecting 2 fuses) and they both aim straight.

Can you verify if the lights are any different with the light switch fully on?

[Ubermensch]

I have no idea if this is your problem, but I just noticed that my litronic aiming sensor on the control arm was broken. You might check this out since it adjusts the position of the lights while driving to compensate for hills. If it's broken I could imagine the sensor drifting up and down causing the syptoms you described. The sensor is on the driver side lower control arm. Just remove your driver side front wheel and look for a small plastic linkage connected to the arm to confirm its in good shape.

Shawn

Edited April 8, 2006 by Ubermensch

[eben]

Thanks for the tip on the owners manual, I had looked at it and found info about removal and changing of bulbs but the aiming was a few pages later. I got the tool out and removed the whole unit...wow it sure comes out easy, no wonder I hear they are theft targets.

Took it apart and founf that the routing for the high voltage cable to the main lamp was binding against the housing. It can be snapped on in any of 4 quadrants 90 degres apart. The little servo motor has to move the main lamp assembly up and down and need this cable to be free moving. Thought this was weird then I remembered I had seen a bulb replacement on one of the maintenance records from the original owner. It was the same side. Put it back together and it now strokes the same as the other one. Excellent!

Also found the sensor on the suspension that Shawn mentioned, it looks OK.

So there are 2 adjustment points one above the other. The lower hole covered by the rubber plug, is the up down reachable with a long he wrench ( maybe 6 mm ). The other plastic blue plug ( that breaks when you try to remove it ) is the lateral side to side adjuster.

It is a very well built unit with connections made simultaneously to electrical, wash water source and drain tube. Very impressive....I like this car!

Eric

[dpolson]

Help! I have a 2002 C4 cab with Litronic and the lights aim themselves very low (100' visibilty or so--very dangerous) about one out of four or five times that I drive the car. The other times, they aim up just fine. Both sides aim equally.

It first happened when I bought the car (used, with 20,000 miles) and the battery was weak. Replacing the battery seemed to help bring the light aim up to approximately normal (though perhaps still just a tab bit low). Manual adjustment seemed to make no difference.

So I began to think it might be voltage-related and I started watching the dashboard voltmeter. There may be a correlation, but since the voltage variations (between 13.4 and 13.8 volts or so) are small, it is difficult to say with certainty that there is a correlation. But it does seem that when the lights aim themselves low, the voltage is relatively low (closer to 13 than 14) and that when they aim up more normally, the voltage is closer to 14.

Has anyone experienced this problem? What is the cuase and the solution? I drive a lot at night with deer on the road and need a solution ASAP. :) Thanks.

[wwest]

Help! I have a 2002 C4 cab with Litronic and the lights aim themselves very low (100' visibilty or so--very dangerous) about one out of four or five times that I drive the car. The other times, they aim up just fine. Both sides aim equally.

It first happened when I bought the car (used, with 20,000 miles) and the battery was weak. Replacing the battery seemed to help bring the light aim up to approximately normal (though perhaps still just a tab bit low). Manual adjustment seemed to make no difference.

So I began to think it might be voltage-related and I started watching the dashboard voltmeter. There may be a correlation, but since the voltage variations (between 13.4 and 13.8 volts or so) are small, it is difficult to say with certainty that there is a correlation. But it does seem that when the lights aim themselves low, the voltage is relatively low (closer to 13 than 14) and that when they aim up more normally, the voltage is closer to 14.

Has anyone experienced this problem? What is the cuase and the solution? I drive a lot at night with deer on the road and need a solution ASAP. :) Thanks.

Provided this was factory installed the angle at which the headlamps "level" too is determined by a height sensor mounted on the rear suspension assembly. If you have rear seat passengers the headlamps will "level" to a lower angle to compensate. This sensor is the most likely place to start trouble-shooting.

The Porsche aftermarket Litronic used a level sensor in a small plastic box generally mounted, velcroed, somewhere in the boot.

Edited July 13, 2006 by wwest

[Meatball]

Do you have the owner's manual? There is detail there on checking and aiming the headlights when they come out of alignment. If you don't have it, download it from this site, I believe the same instructions are there too.

I have daylight running lights in mine too (not from factory, but just by connecting 2 fuses) and they both aim straight.

Can you verify if the lights are any different with the light switch fully on?

I am intrigued by you mentioning getting daylight running lights by connecting two fuses. Can you elaborate?

Thanks,

[Cloudsurfer]

Having just done the retrofit install on my 986 Boxster S, the "little black box in the boot" is only there to allow the low beams to swivel up 5 degrees when you engage the high beams. It does nothing to auto level the low beams.

Patrick