Park Assist Bites the Dust - Assistance Sought

[spooltime]

Yesterday as I was backing out of my garage, the display lights on the front Park Assist indicator panel starting flashing very erratically - blinking in no particular pattern and then suddenly nothing. The Park Assist is just simply dead. Personally, I find the Park Assist a very useful feature on a large vehicle and even after only one day, I'm already wishing it was still working.

First thing I did was check the fuse on the passenger side fuse box (#2 fuse, 5 amp for those interested). Fuse was fine. Next I tooked a peek at the diagnostic manual and discovered that there's a plethora of possible fault codes related to the Park Assist system, so it was time to hook up the Durametric. Unfortunately, although the Durametric has Park Assist coverage for some models, an '06 Cayenne is not one of them. My guess at this point, based on the way it died, is that the control unit failed, but that's just a guess. It will have to go into the dealer for diagnosis and repair, but before it goes in, I'm wondering if there are any other simple tests I could do or things to look at before biting the bullet on a dealer repair?

Edited July 15, 2013 by spooltime

[wvicary]

I have seen damage to the rear wiring harness and sensors from road debris. Is your Durametric software up to date?

[spooltime]

I have seen damage to the rear wiring harness and sensors from road debris. Is your Durametric software up to date?

I have the current software version installed. It shows the PA module when I bring the program up manually, before hooking up the vehicle, but when I have it initiate by starting the program with the ignition on, the PA module isn't there. I've contact Durametric support to see if PA is supported on '06 Cayennes.

[hahnmgh63]

Durametric found a bad (Intermittent) Park Assist sensor on my '06 CTTS, I would assume they're the same sensors on your '06.

[deilenberger]

Just a crude test (if it's like BMW's systems) - when park-assist is on if you have good ears you can hear the sensors. Put your ears right up against them and listen. Good ones sound like a cricket.. bad ones sound like nothing.

[spooltime]

Durametric found a bad (Intermittent) Park Assist sensor on my '06 CTTS, I would assume they're the same sensors on your '06.

That's good to know. Since I'm thinking the PA control unit died, is it possible that since the control unit is effectively "offline", that there's nothing for Durametric to survey related to the PA system? Or should it tell me there's a problem with the PA control unit?

Also, the PA on/off switch in the overhead console is just dead - no power on/off illumnation. Again, I've already checked the fuse and confirmed it's good.

Edited July 19, 2013 by spooltime

[spooltime]

A further update. After sorting out my Durametric issues, I got a P1327 fault code, which is a "no communication/signal" with control module. Further that terminals 5 and 15 were inactive. I'm pretty sure that means the module itself died. Replacing the module looks easy, but it does require coding to the vehicle, which I'm pretty certain the Durametric can't do. Am I missing anything here?

[spooltime]

It's taken me quite awhile to get around dealing with this. As noted above, I concluded my Park Assist control module had died. I was able to source a used control module from a salvaged '06 CTTS, my thought being that since it was the exact same year and model as mine, it would already be correctly coded. A new module lists for about $220, and I paid $105 for the used one, so it was worth taking a chance with it and not making a trip to the dealer for coding the unit.

Sadly, the PA control unit is buried behind the side panel in the rear luggage compartment. There is some serious diassembly required to be able to remove the side panels, but with two related projects also lined up (rear hatch strut replacements and Dension install), it seemed worthwhile to suffer through disassembling the interior lining of the rear half of the vehicle.

If I find the time later, I'll post a DIY rear trim removal tutorial. But for now, here's a shot of the rear compartnent sans trim panels (yes, the rear seatback must be removed in order to remove the trim side panels):

If you ever wondered what the mechanicals of the 4-zone air conditioning equipment look like, take a peek:

And all of this work just to get to the small PA control unit located at the very bottom with a sliver label on it. It was buried beneath the AC equipment, but with a little wiggling around, I was able to remove the dead unit and install its replacement:

Moment of truth after plugging the replacement control module in and starting the vehicle up - it worked!!!!! And I now have my Park Assist back again after living without it for about 4 months. Tomorrow, I will install the Dension unit and then wait for the new seals to come in for the hatch struts. I'm leaving the trim off until all of the rear compartment projects are finished.

Edited November 11, 2013 by spooltime

[hajen]

New to this forum the the Porsche world.

My rear PDC don't work the indication light's all go red and a 'long' beep to go with same. once R is engaged. the front one work fine.

Any good tips for how to pinpoint which sensor(s) is the busted? And do the full bumper need to come down to replace them?

//PB

[hahnmgh63]

I don't think you have much of a choice but to get the Durametric software and install it on a laptop. If you plan on keeping your Cayenne or have another '96 or later Porsche then it is a must anyways. If not, maybe you can find a local Porsche dealer that will do a Scan of your car with their PIWIS machine for free or at a discount?

[hajen]

Thanks, have suspected so. Order on a Durametric is placed...

[hajen]

So, got the Durametric up and running. - great tool.

Question regarding the Park *** sensors; I have three fault codes on the rear, left & right outer and rear right center?

Is center the one closest to the car centerline or is it the one between the outer and most center one?

thanks

//PB

[hajen]

Thought I should give an update and what hopefully is closure...

1st - center sensor is the one between outer and inner.

2nd - Due time constraints I went ro the Porsche stealership and bought three sensors (approx 100 €/pc). dismantled rear lights and all the plastic stuff (wheel house linigs and aft chaperon (spelling?). Broke some of the small bolts that were completely corroded, whereof one for the right rear light. took some drilling and alot of blody time... replaced the three sensors, done in a blink and put all stuff back. Still not working and get same fault msg's...

Two day's later, without anything done - the rear sensors star working, and it still work... Good i say...

otherwise I need say, since this is my first Porsch, what a car.

//PB