Having an issue with my 09 v6 Cayenne, about two weeks ago an error came on saying brake proportioning and the car was locked in park. I was able to wait 15 minutes and the error went away, however when I went to start the car again it would not start regardless of how long I waited. Now it is also showing an Ignition Lock Fault when the car is unlocked regardless if the key is in the ignition or not. I can insert and remove the key but the car won't turn over.

When I searched other forums, the only recommended solution I found was to replace the battery. Well I did that today and still have the same problems. Was I supposed to reset the ECU too? I would have thought by removing the negative battery cable off this would have reset the ECU.

Anyone have any ideas? I am on the bottom of the third floor parking garage and can't get it out of park nor have a flatbed tow me out.

 

Im going to throw this out there as a possibility....
Have you (or someone/shop/etc) check the wiring harness in the drivers side footwell area for moisture? It is possible that 3 crimped connections got moisture in them and have corroded, no longer allowing your vehicle to start or probably come out of park. It's fairly easy to check, just pull the carpet back along the edge of the door sill up along by where the hood release/dead pedal is and feel it. Even if it feels ok, I would open it up and check the 3 small crimped connections, and if there is ANY doubt, re-do them. It's definitely worth checking, hope this helps.

 

Wow while searching. My cayenne was just taken to the shop today due to the brake proporting light and ignition lock. I actually thought I caused it. I was at the light and hit the brake and gas to launch the car to pass another car to get into the highway. As I entered the highway the brake light came on along with the ignition lock. Car was stuck in park. The car is at the dealer. Let's see what they say. My carpet did seemed a ill wet on both pass and driver side. I hope this isn't expensive. I'll keep you posted.

 

Ok i got the car back form the shop due to the brake proportioning and ignition lock error code. This is was happened. The issue was part my fault. While at a red light i was trying to launch my Cayenne S to get into the right lane to turn onto the high way. Well i stepped on the brakes and gas at the same time and launch the car! Boy did it launched. Within 30 secs the light came on. So i was forced to pull over. When i parked the car was stuck in park mode. I had to get the car towed in. Here were the findings...

1. Apparently the ABS brake sensor on the passenger front wheel became loose when i did that power launch. This was a simple fix. They just reconnected the sensor. This will cause the transmission to lock since the abs is disabled.

2. The ignition lock failure is electrical related. I had a clogged ac drain which was causing the ac built up to drain inside the car!! Over time this drain issue started corroding the main harness under the drivers carpet. When i did a hard turn onto the highway, the spillage got into the bare harness which cause the malfunction.

The fix was simple. No indy shop wanted to accept the repairs. I was actually happy to have taken the car to the dealer. If you are having this issue. drive the car hard on curves see if there are any leaks while turning hard. Cayennes the dealer said are known for leaking inside the cabin. If your drains are not cleaned they clog up causing this. The dealer had to sawter the wires back. if so you can do it yourself. Remove the driver carpet inspect the main wire harness. Make sure the lines are not corroded. Also check your brake sensors at the caliper to make sure the connections are good and that there isn't anything loose. I had a bill $$$ but luckily i didn't need any parts.

And one more thing.... don't launch the cayenne.. lol i learned my lesson.

 

Great! Glad that you got it working and thank you for updating your thread for others to reference moving forward.

 

This was the issue for me - sure would be cool to have a write up... I did do the battery first and it was def the corroded wiring. Not worth the repair at the dealership if it really was as simple as it sounded to fix the wiring.

 

Completely forgot to update this thread, my issue was that one of the wires along the driver side footwell became disconnected. You can see in the picture below where I attached it with a red connector.

 

similar problems happen to me. I could not connect to the DME via durametric tho. I had my injectors replaced ( original one went bad ) did a power launch that night. Next morning drove fine then lunch time come around went for another drive brake proporting light came on and then went away. Came home turned off the car went in get my computer and durametric cable. Then I get air suspension failure. Plugged in my durametric and try to do the scan TCM came back could not find DME, same goes for leveling system. Tried the Engine DME said could not communicate.

Next morning called up my friend who know a tech at local porsche independent shop to come over with a piwis. They were nice enough to came by with their piwis on the spot. Plugged in and all he said was maybe a dead DME. I could not connect to it.

DME gone bad?? or could it just be bad wiring. I could not start the car. Could on the switch but a flat ignition. silence...

 

I would check the voltage on the car to make sure the battery isn't dead. When the battery goes bad on any Porsche, you will get many warning lights and ignition failure including a dead DME.

Next check the wire harness at the driver side under the carpet. You may have corrosion. Cayenne are known to have issues here. I speak from experience.

 

Checked the wirings underneath the carpet. All good no corrosion no water. Bad relays maybe not sure. Battery is brand new 1 day old. I guess I really have a dead DME.

 

After a couple days of heavy rain all of a sudden I got a multitude of issues with my newly bought cayenne v6 '08
Got the famous brake proportioning and faulty lock warnings ,my speedometer didnt work ,my backup camera and back windshield wiper didnt work ,my parking sensors stop working ,sport button etc. My v6 its a manual so I didn't have issues with not being able to drive it. It's was very annoying to drive it because I think one of the valves in the engine stoped working as well so Everytime I was taking the foot or the acceleration pedal it was starting to shake like I was in high gear with low rpm which wasn't the case.
Got it to my local shop after I've done some research online and read this helpfull post and told my mechanic to check the wire harness. The carpet was wet so I was hoping that was the problem
The guy checked the harness but didn't split it and check every wire and that cost us like extra 4-5 hours of work and a $300 battery change.my old battery was weak anyway so I did t mind the new one I new it was a matter of time. Shop was nice and didn't charge me for the extra time since I've insisted to recheck the harness and this time we did found 4 wires split and another couple with problems from moisture.
Stil didn't figure how my carpet got so wet but as soon as the nice weather is coming I'll put the hose on it after I remove the carpet
Good luck with your problem and I hope the info helped

 

All the info on here is great; just one more thing; the wire that needs to be repaired is under the foot rest/dead pedal. So you will need to remove the carpet and foot rest to get to it.

 

Hi Guys:

Reading this post, I deduce that the issue of water at the foothall driver side (left side of car) can be a cause of the warning of failure in suspension that appears on a random form in my car. Can also this water make that the car is 2 to 3 cm lower at the driver side (rear and front) compare to passenger side no mather that air suspension is working ok?

Thanks for any hint on this.

Paul Georg Grote

Cayenne S 2006 92.000 Km Chile

 

Old thread, but hoping someone could still help. 2009 Cayenne. I had a small leak this past year, water was getting in the grommet that allows the door wiring harness to enter the body but went un-noticed.

Anyways must have been pretty little, as I never noticed till we had a recent heavy rain storm and my door panel got wet as it dumped back in that way.

I keep reading about crimped connectors, and I have all the same errors as the previous poster.

I finally got the carpet up, and didn't damage too much, it was damp, but not soaked, and I could see a brown red rust trail from water over time that dried and left marks on the body of the cars sheet metal.

Is the first black box that all the wires go into what I need to open?

And in there I should just find bare crimps? Wondering what I am looking for.

Any pics from previous exploits would help.