jimbomgee

Excellent post.

My situation seemed to be exactly as yours...

I had steering lock fail and brake proportioning errors plus ABS, airbag, check engine lights.
I could hear the steering lock mechanism engage and disengage whenever I inserted or removed the key.

When I tried to start, it would not start with prompt for brake press; display would toggle between steering lock failure and brake proportioning but I found that it wasn't recognizing brake pedal press and that didn't matter because if I tried to start again it would start anyway but would not move out of park because of the steering lock error.

I found the same corroded lead you found. Nothing left of it except copper dust. I had seen some other forum posts about the same problem but yours seems to be the most well written and helped me the most. Thanks much!

One notable is that I pulled the carpet back without having to disturb the driver seat. I ended up moving the seat anyway so I could give everything in the bundle and around the battery a good once-over inspection. This also gave me opportunity to do some good cleaning vacuuming in those hard to reach places under and around the seat.

Great job, my friend.

vandal968

What could possibly be the purpose of those rubber drain plugs that clog? They're hidden behind the plastic fender shrouds, so it's not like they keep sand and dirt from blowing up into the engine compartment from below. Are they there simply to break the car? What am I missing?

c

touareg

I believe it is supposed to be a one way valve, so when water hits up, it does not get in the cowell area.

jeanmarcboilard

I've read they're to keep critters from getting up in there.

touareg

Santy Claus maybe?

Hesh1975

Aza

Excellent post that helped me clear my ignition switch/ brake proportioning error. Whilst the car now starts I have the PSM warning light on - the car did not have this fault, and there is no codes present now.

The only difference I can see is the red/yellow wires- two in the Porshe bulletin about but I have three. I'm sure they came from the same 'wrap' but it all disintegrated trying to find these joins.

Have I assumed wrongly?


Aza

touareg

Check your relay 443, also I had weird PSM problems for a while, turned out I had load on the same circuit as the PSM module. This system is critical and the car will shut down a lot of stuff on the hint of the slightest error, in the name of safety. Your battery may be going slightly bad too.

Knock on carbon fiber trim, I have had 0 problems after the harness repair and 443 relay replacement for over a year now.

Unfortunately the temp sensor at the back of the head was bad, and I had to replace it.

Tblue24me

Excellent series of posts and directions on clearing the wet floor/wire corrosion issues due to clogged drains.

Item 1.

I have a 2006 v6 and have been very happy with it but the vehicle does require a lot of attention. Makes for a great hobbie. Anyhow, after chasing the sun roof drains cleaning as well as the cowl drains (a ton of debris fell from.both cowl drains) I found an additional area where water enters the car. I disassembled my roof rack mounts (not a roof rack..the actual mounts that sit in a fairly deep trough that holds water all the way down the vehicle on each side) that simply screw into the metal roof panel. The 5 screws each side simply screw thru the mount and directly through the roof and into the cabin covered by...wait for it....the head liner nothing else. Remove the screws and you can see directly into the cabin once the headliner is removed. I pulled the mount off on each side and found terribly disintegrated rectangular thin rubber seals between the mount the roof outside. I checked the headliner and it was clear, from staining, that each hole on each side leaks onto the headliner. I removed the screws and rubber seals and silicon caulked each hole put the rubber seal back on the more silicon, then the roof rack mount then more silicon the fed each screw through and tightened. Then siliconed it on top. Hopefully this makes the vehicle along with the other sun roof and cowl drain cleanings free from water entering the vehcile.

Item 2.

I lifted carpet on the passenger side and no splices to wiring loom so i put everything back together and head over to the driver side. I lifted my driver side carpeting, found the wire loom, it's splices (2 thin red wires, 2 thin black wires, 3 thicker red and yellow wires and 4 thick pressed together black wires each splice or connection having a high level of corrosion as described above in precious entries. I performed the necessary surgery on each splice/connection and im quite confident I have a sealed, dry, clean and corrosion free wiring loom driver side. I put everything back together connect the battery, car starts and runs/drives but no brake lights and front driver side yellow parking light on front right quarter panel. Also the rear hatch and wiper will not operate. I plug durametric up and still all the codes are present. All CAN BUS's are not connecting and cannot clear all the numerous codes. So I order a 433 relay as described a few entries above and Glen at Pelican Parts, who was really.helpful tells me it has a new part number 7N0-951-253 Starter relay. The relay is correct 12v 50a and the 5 point connections r oriented right. I paid for 2-3 day shioping and got it in 2 days...sweet. Put ever thing back together, run durametric and still tons of codes and can not connect to modules/can bus errors.

car is dry/ran dehumidifier for a week and pulled all water out dry under the carpets. If anyone can further comment I would really appreciate it. Rennlist.com is a wealth of knowledge and helps me on both my cayenne and 2007 base cayman. Tons of fun both cars...girlfriend loves them both as well. The dogs love the cayenne. Thanks again for all the knowledge, contributors and any help anyone can offer.

deilenberger

When you pulled up the passenger side carpeting - did you take the tape off the wiring harness? Often the splices are hiding on wires inside the bundle of wiring and not easily visible without taking the tape off and spreading the wiring out. Also - some people have found corroded splices further up the wiring harnesses - on the drivers side people have found splices up under where the wire bundle goes under the dead-pedal. And part of the harness on the right side continues up into the A pillar - and if you had a plugged sunroof drain, water has been dripping down the harness and through your fusebox..

It would be useful if you can post a list of all the fault codes and their titles that Durametric found..

Tblue24me

Thanks deillenberger. You are right, I checked further up the driver side wiring loom and found 3 additional splices but none were corroded so I left them alone with fresh wraps. I thoroughly checked as far up the loom as I could but the bottom of the dash board limited my effort. I then went to the passenger side and checked all the way to the dash board and unwrapped everything but there were no splices on that side. I then ran my durametric again and here are the codes listed by durametric module:

Engine ME
p1634 CAN timeout- air conditioning
p1632 CAN timeout- cruise control
p1625 CAN timeout-instrument cluster
p1637 CAN timeout-vehicle electrical system control module
all the above codes were followed by implausible signal test conditions are not completed, fault is not currently active and is not causing a DTC

Instrument Cluster
1299 Gateway-
1330 Rear convenience system control module-
459 PCM2
all the above codes were followed by no signal/communication test conditions not complete fault is active and is not causing a DTC

Stability Management- PSM, Airbag, Steering Wheel, Alarm, Electrical System, Tow Bar, Wipers, Transfer Case, and Tow Bar modules all showed:
Communications error unable to connect/communicate to this module

Gateway
1330 rear convenience system control module
1305 Can infotainment
459 PCM2

Air conditioning
1299 Gateway implausible signal
1330 rear. Convenience system control module no signal/communications.

that's it. I'm not sure where to go next with this. Anyone any ideas?

Tblue24me

I will add that when I first experienced problems was after a ridiculusly hard long rain. Problems were the alarm sounded erratically, the tail and 3rd brake lights were bright ride, rear hatch wiper wouldn't shut off and rear hatch coStanly tried to unlock itself. I notice ld.ponding water in passenger side rear cubby in cargo area..right were several large wires are grounded. No water in spare wheel well.

VulcanGrey

I'd go redo, or at least waterproof those other splices as well... The fabric tape they used gets wet and that moisture causes the wiring to cross-talk, which confuses the ECU's. The corrosion isn't the only reason those splices are a source of problems.

deilenberger

All the error codes seem to be CAN-BUS related - difficulty in communications over the bus. I have no idea if Porsche has the tools to analyze the actual bus wiring. In my old days of troubleshooting networks, we'd put a packet capture device on the bus and see what was getting lost, and also use another tool that can "ring" out faults in the wiring by distance from where it was connected, and also check for open circuits - which can cause the entire bus to misbehave due to unterminated bus legs (which causes odd reflected packets to go back on the bus and confuse the heck out of everything.

I think you want to pay close attention to any wiring with the color orange in it. Porsche seemed to use orange wire in combination with other color stripes on the orange - for computer data bus lines. I see no other orange wiring in the wiring diagrams. Orange-green and orange-brown and orange-black are the primary CAN data bus lines. Any wire with brown in it - can be assumed to be the "ground" side of the circuit - or as it's called in data buses - the "low" side. Orange-brown is universally the low side of the can bus. The orange-green and orange-black are the "high" side - and actually carry the digital signal.

The "Gateway" is where all the data circuits get together to play with each other (get sorted out and sent on their way to the devices they are supposed to control or provide control for.) And your errors indicate that for some devices - the gateway can't perform it's functions correctly.

Again - I'll stress that the splices - especially if any are found in the data lines - are suspect. If you haven't taken the coverings off the splices you found - you should. You want to examine the actual junction of the two wires. They should be either soldered together, or a crush type barrel sort of connect is used to join them. If anything looks at all odd about these junctions - it's time to learn to use a soldering iron, and redo them and then cover them with waterproof shrink wrap (that has a goo inside that softens up when it's heated and then is compressed around the wiring by the shrinking exterior plastic.) Thing is - the wire can actually fail some distance away from the actual junction due to "capillary action" (Google it) - pulling water up between the strands of the wires that eventually corrodes the bare copper wire inside the insulation. To look for this - you want to flex the wiring with your fingers. If any part of it feels odd or crunchy when flexing it - that's a suspect part of the wiring.

If all of this sounds like Greek to you - then it's probably time to try to seek out a mechanic who also happens to have a degree in electrical engineering. They're rather rare - I know of one in NJ - but he's the only one I know. If you can't find one - then you have to find a place with the diagnostics equipment to suss out the problem.

As my father-in-law (RIP) used to say "It's all communications.." - and in this case - that's what it sounds like to me. Your modules aren't talking to each other, so either it's wiring related (most likely) or one or more have failed in a manner that causes interference on the data bus.

BTW - if you become a "Member" here (ie - paid $18/year and you get a nice sticker for your car..) you can then add a "SIG" that you could use to provide useful info like your actual name, where you're located, what sort of Porsche you own (year/model) and most anything esle you'd like the world of Porsche people to know about you. The reason this might be of value is - someone in your area may have some experience in your problem area and might just offer to help you troubleshoot it. Or not - your choice - your money.

Good luck!

deilenberger

BTW - I seem to recall reading some threads mentioning the Durametric does have issues with later model software in connecting to the Gateway. You may want to search for "Durametric" "Gateway" using the advanced search function, and see what turns up. Not sure if this was the 955/957 or 958 that experienced the problems.