Toby Pennycuff

According to the Service Information Technik manual for the Cayenne S and Cayenne Turbo, each wheel has an active speed sensor that feeds information to the PSM control module (pp. 4.69-4.70). "4511 Active Speed Sensor The speed sensors provide information to the PSM control module about wheel speed. The speed sensors on the Cayenne are described as 'active speed sensors.' Active speed sensors require an external power supply. A two-wire cable provides the connection to the control module. The active speed sensor is supplied with power and ground by the PSM control module. Operation of the sensor element integrated in the active speed sensor is based on the change in a resistance within an electronic system, depending on the strength and direction of a magnetic field. The pulse generator for the active speed sensor is integrated in the wheel bearng in the form of small magnetic plates in the seal ring. As a result of the rotational motion of the wheel bearing/seal ring the resistance in the sensor elements of the active speed sensor changes. The change in resistance is converted into a digital speed signal by an electronic circuit in the sensor element and transmitted to the PSM control module." Page 4.70 shows a diagram of the speed sensor. Hope this helps.

Oh, it's not possible. It's real. And I called PCNA this morning at 0705 CST. The call center rep was very nice, but had no information about either recall (wiring harness in engine bay or transfer case) yet! Their suggestion was for me to contact my dealer. Toby

Loren, Are part numbers out for the Carrera GT yet? If so, is there a part number assigned to the Becker radio for the C-GT? This would be the Becker Online Pro 7800. Curious about part number, availability in US and projected price. Thanks! Toby

wingless, It's not clear that they are connected (directly) to the CAN-bus. The Technik manual clearly notes a Xenon control unit, but I cannot find any reference in PET to such a control unit. If this control unit does exist, I am guessing that it controls the bending of the headlight beam as you turn, and works in conjunction with the leveling sensors and speed sensors on the vehicle to keep the lights properly leveled. There's no doubt in my mind that the PST2 is required to hook in and update the system to the fact that Bi-Xenons are present. I had to do exactly that on my 03 ML350. Once that change was made, my Bi-Xenon projectors worked just fine. I'm pretty sure that Porsche would do something similar. I'm still unclear on whether there is a (physical) Xenon control unit or not and how the wiring is pinned in the connectors. With those pieces of info, I think I can come up with a Bi-Xenon upgrade for Cayenne owners who are stuck with halogens and want Bi-Xenons. TBP

Loren, Did you see my original request on this topic? I still have not been able to find a source that can tell me whether there is a dedicated Xenon control unit on the CAN bus and if so, what its part number is. Do you have any clues on this? Also, have you broken down one of the Bi-Xenon headlight units? I'm curious about two things... 1. Is there a connection from the ballast to the bulb via part 955 631 239 20? I am assuming that the ballast component (955 631 193 00) depicts the two connectors in illustration 905-01 (the left-most in the drawing being the connection from the main harness connector and the right, smaller connector where 955 631 239 20 would plug in, with the other end of the connection onto the D1S 35W bulb (N 105 661 01). Does that look correct to you? 2. Is there any wiring diagram that shows the pin-outs of the connectors on the Bi-Xenon housing versus the Halogen housing? In other words, is 955 631 239 10 for the Bi-Xenon assembly (the Headlamp Harness) pinned differently in one or both connectors when compared to 955 631 239 00 (the Headlamp Harness) for the Halogen connector? The reason I'm asking is that if the Headlamp Harness is wired the same way, this could be a pretty straightforward conversion project. I'm just trying to find a way to figure out if the wiring and connectors are different for these two parts. Any help or direction you might be able to offer would be most appreciated! Gert, if you're reading this, perhaps this is an upgrade that Carnewal can offer to us poor schmucks who wanted Bi-Xenons but didn't want to wait for a vehicle to arrive with them, thus were stuck (like me!) with halogen headlights instead! Just a thought. I know Performance Products sold the Bi-Xenon projector units for ML owners and did pretty well. The problem was that the connecting harness was not pinned properly. Once you got the wires connected properly..... VOILA! former halogen vehicles were suddenly Bi-Xenon vehicles! Toby

Loren, I have scoured my copy of PET and cannot find any specific reference to the Xenon Control Unit. From what I can glean from my "Service Information Technik" manual, the Xenon control unit interfaces on the CAN-bus to help calculate light bending characteristics for the Bi-Xenon headlight unit (page 9.18). The control unit is described in the schematic found on pp. 9.8-9.9. Specifically, the Xenon control unit is depicted as control unit number 12 attached to the CAN drive unit. Since I'm giving serious consideration to trying to do the science project and upgrade my headlights to the Bi-Xenon units, I'm really curious if this Xenon Control Unit is an actual part or merely part of the programming maps on the CAN drive unit. Can you offer any suggestions or information???? Toby (P.S. - is my-porsche.com dead? They seem to have been off-line for quite some time. I still have not found a source for the Cayenne manual sets!)

Loren, Do you know what kind of control unit this part number is? Thanks. Toby

Kevin, You are correct. You have to remove the lower valence to get at the assemblies for the fog lights. You can probably get at it from under the car, but it's easier to get at them by removing the lower valence. Happy New Year! Toby

Got 'em. Many thanks Loren! Toby

Loren, Thanks for the drawings. Do you have the pages that show part numbers ofr items number 16 and 21 on the Bi-Xenon side and item number 17 on the halogen side? These are the pigtails that connect into the wiring harness on the body. Thanks! Toby P.S. - the Bi-Xenon unit price (#1 in the drawing) was quoted by Park Place Porsche-Dallas at $522. Bi-Xenon bulb (#2)= $220. Ballast (#15) = $356. Cable (#21) = $34. Cable (#16) = $34. Yowser! TBP

Thanks Loren. I'm just re-surfacing from having to re-build my machine (computer) all day long. :soapbox: Anyway, I'm just about done, so I will check it out. I also have some pricing for some of the Bi-Xenon parts. It's not cheap........ Thanks again. Toby

Loren (or anyone else), Are you aware of any control unit differences that would prevent me from undertaking the Bi-Xenon upgrade science project? I checked with my dealer, and it looks like you can buy the requisite parts to do the upgrade. What you would likely NOT get out of the upgrade would be the headlight washers and the auto-leveling/light bending features. Neither of these is crucial to me as 1) I keep my light covers clean (avoids the glare problem) and 2) I do not carry heavy loads that change the vehicle's geometry. From the diagrams I saw (without part numbers! :soapbox: ), the housing assembly comes with all the basic parts. Thus the order would include the base housing, the ballast, the bulb itself, and the wiring harness pigtail. Do the Cayenne manuals describe any other differences between the halogen and Bi-Xenon setups? Just curious. Since I bought my "S" off of the dealer's floor, and it was an aearly run, the dealer had not ordered the car with Bi-Xenons! :censored: I'm getting tired of driving with halogens and want to upgrade to Bi-Xenons. I know that Porsche has not released a Tequipment upgrade, nor has anyone else, but this should not be a big deal. I did this upgrade on my 03 ML350 and it worked like a charm. The upgrade required some investigation on the wiring harness and movement of some pins in the pigtail to line up properly. Once done, I got my MB service tech to change the control unit setting from halogen to Bi-Xenon and it all worked fine! (Apparently, MB manages the voltage and amperage to the headlights, so a setting of halogen prevented the ballast from getting enough juice to fire the lights up. It caused the lights to strobe madly.) Anyway, would apprecaite your thoughts on this before I go drop north of $2K on a science project! :o Thanks. Toby

Loren, Is there any way to tell if a particular TSB should or should not be applied given a VIN? Also, are these TSB's available as addenda to the Factory Service Manuals? Thanks!