KERNELCLIFF

There is a microswitch in the door latch assembly that has probably failed. The bad news: -Porsche does not offer this part separately from the $500 actuator. -The Chinese microswitches on Ebay and Amazon, while inexpensive, may or may not be a perfect fit and take a while to arrive -The process of accessing the actuator is fairly involved. The process of realigning the door frame after reassembly is particularly fiddly IMO. The whole procedure is documented elsewhere on this site. Be aware that there are model year differences in how the lock cylinder is removed that are not well documented! The good news: -There are complete aftermarket actuator assemblies that are a perfect fit for $40-60 on Ebay- I bought one and just swapped out the switch on my existing actuator and tossed the Ebay part in my spares bin. -Some people claim that you can clean the switch but mine was so deteriorated it wasn't an option, and given the labor involved I would replace the part(s). The job took me about 5 hours including puzzling over the lock cylinder and adjusting the door frame.. Given that the job may run you about $1,000 in parts and labor at the dealership, $60 and an afternoon of aggravation doesn't seem like a bad deal.

My 2009 Cayenne base with 110,000 miles displays CEL and posts a P0674 fuel rail overpressure, implausible value via Durametric. (Unfortunately the actual vales are not shown by the software for the v6.) There are no problems with startup, rough idle, loss of power, etc. Just that annoying CEL. There seems to be a fair amount of conflicting interpretations of the P0674 on the web, and the absence of symptoms is puzzling. Before my questions, some history. About 14 months ago, I had what was diagnosed by a local shop as a failing PCV, requiring replacement of the intake manifold, and while we were in there also premptively did the pressure sensor, high pressure fuel pump and the camshaft plug. Ouch. Expensive. And now outside the warranty on the parts. So, my questions: Its hard to believe that the PCV is failing again after only 5k miles, and without the usual symptoms of same. Why/how would a failing pcv valve cause the overpressure condition anyway?? (BTW, the old hand over the oil filler procedure doesn't affect the idle either). How likely is it to be a bad high pressure sensor, since I had that replaced too? From what I can find on the electrical characteristics of the sensor it does not seem that a false high reading would result from failure mode. Could it be a fault in the high pressure fuel pump-particularly the internal pressure relief device? My dilemma is this: A new sensor is cheap, but the procedure for replacement requires removal of the intake manifold and seems pretty nasty for DIY, or involves a lot of expensive labor charges from a shop. On the other hand replacement of the high pressure fuel pump looks pretty straightforward, and I can get the part for about $275 and the plastic cam plug for about $60 (really??). I'm not usually one to throw parts at a problem, but in this case, while not exactly cheap, I am inclined to replace the HP fuel pump myself and see if it solves the problem before springing for the cost of labor to have a mechanic throw other parts at it! Any thoughts you gurus out there might have would be most appreciated.

I appreciate the detailed procedure, but before I embark on this apparently fiddly project I hope someone out there could address a few questions regarding my 2009 Cayenne 3.6 did with 120k miles. I am getting a P0674 code from Durametric-which suggests the pressure sensor is supplying an implausible high value. There are no problems with startup, rough idle, loss of power, etc. Just that annoying CEL. There seems to be a fair amount of conflicting interpretations of the P0674 on the web, and the absence of symptoms is puzzling Why/how would a failing pcv valve cause this (BTW, I had the manifold professionally replaced 14 months ago)? The old hand over the oil filler procedure doesn't suggest it is the pcv. How likely is it to be a bad high pressure sensor (had that replaced too)? Am I correct that the same procedures are required to access that? Anyone know the electrical characteristics of the sensor or if it reads high when it fails? Could it be a fault in the high pressure fuel pump-particularly the internal pressure relief device (yep, replaced the pump WYIT preventatively 14 months ago, too)? Refitting a new pump would be an easier DIY fix, but an expensive part to throw at the problem. Any advice would be welcome-thanks in advance. ~~~FOLLOW UP TO ORIGINAL POST~~~ So, replaced the sensor, it is actually accessible without removing the manifold. Hardest part is unclipping the electrical connector. Cleared codes, returned after about 25 miles. Replced HP fuel pump with new Hitachi pump. Procedure is different from the v8 diy posts, pump shaft is perpendicular to the camshaft and apparently driven by a lobe rather than inline with the camshaft via the clutch described for the v8s. Good news is you don't need the $70 plastic plug with this application. Close quarters, as with all P-car repairs, but not too difficult, need some stubby metric wrenches for fuel lines and long reach torx T-27 socket for the 3 screws holding the pump. Took maybe 2 hours start to finish. Starts and runs great, but unfortunately CEL returns. At the end of ideas as to how to address this problem. Any suggestions?

I have reviewed the past posts regarding the high speed fan hack for the 986/996 by manually switching lug 85 to ground. What is the easiest/best way to tap that lug so I can run it through a switch, and what gauge of wire is called for? Thanks!