Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Bizarre electrical issue rear

911nick
 Share

Recommended Posts

911nick Member

911nick

Posted
Posted (edited)

The Porsche gods must really hate me right now because my Cayenne is doing all kinds of weird things. The Cayenne was parked outside in the rain last night. I was woken up by its alarm going off. I went outside to investigate. The rear hatch and glass were both unhitched, meaning the actuator motors for each had unlocked without someone actuating them. Now, neither the rear glass nor the hatch open. I could not turn off the alarm. It finally silenced itself. There is no sign of forced entry, so I'm ruling out that. In addition, the brake lights are stuck on no matter if the ignition is on or off. Also, the rear wiper does not work as well as the rear defroster. Shortly after starting the car, I smelled something burning coming from the rear interior. I replaced the battery seven months ago. Help! What is going on?

Edited by 911nick
ekstroemtj Member

ekstroemtj

Posted
Posted

Rain/ electric problems...

i assume you already investigate if there is water somewhere inside your car?! The typical problem under the floor mats driver side / passenger side.

911nick Member

911nick

Posted
  • Author
Posted
Quote

i assume you already investigate if there is water somewhere inside your car?! The typical problem under the floor mats driver side / passenger side.

 

No water under the floor mats. There was some moisture on the right rear pillar and some on the rear headliner, but that was likely due to rain entering an open hatch and glass.

ekstroemtj Member

ekstroemtj

Posted
Posted

I had a Cayenne on the street for a very long time without driving. Battery very poor. The first things which are getting crazy during turning the key first time. Rear hatch. PSM light. 

In my case the problem is a weak battery 

lewisweller Member

lewisweller

Posted
Posted

Check the rear comfort control module for water damage or unrelated issue which is not water damage but module or wire harness failure to the module. 

It located behind the CD autochanger. Right side of the boot as you enter the boot hatch behind side trim panels. 

This module controls all the items you mentioned are having faults. 

Replacement of module involves recoding which isn't difficult with vcds or durametric but coding the existing keys to the new/replacement module is a Porsche piwis job apparently, if I could work out how to do key coding with my vcds I would have replaced mine to fix check tail light issue when pressing brake. 

  • Upvote 1
911nick Member

911nick

Posted
  • Author
Posted
Quote

 

Check the rear comfort control module for water damage or unrelated issue which is not water damage but module or wire harness failure to the module. 

It located behind the CD autochanger. Right side of the boot as you enter the boot hatch behind side trim panels. 

This module controls all the items you mentioned are having faults. 

Replacement of module involves recoding which isn't difficult with vcds or durametric but coding the existing keys to the new/replacement module is a Porsche piwis job apparently, if I could work out how to do key coding with my vcds I would have replaced mine to fix check tail light issue when pressing brake. 

 

 

Ah, so there is a module for all this stuff. Thanks! Now I have a direction at least.

911nick Member

911nick

Posted
  • Author
Posted

I made some great progress today thanks to Mr. Weller. The module was exactly where he said it would be. I opened it up, and sure enough there was a bit of moisture inside along with a destroyed capacitor. I was able to get a used one sold locally.  We will see how it works tomorrow when I install it. I will post results.

  • Upvote 1
lewisweller Member

lewisweller

Posted
Posted (edited)
9 hours ago, 911nick said:

I made some great progress today thanks to Mr. Weller. The module was exactly where he said it would be. I opened it up, and sure enough there was a bit of moisture inside along with a destroyed capacitor. I was able to get a used one sold locally.  We will see how it works tomorrow when I install it. I will post results.

No problem at all happy to help. Some pictures of your repair would be fantastic pls. 

Edited by lewisweller
911nick Member

911nick

Posted
  • Author
Posted

Lewis' diagnosis was spot on. I installed the new box, and everything works like it should! This repair only cost me $50. Lewis, you really saved my bacon. Ekstroemtj, I appreciate your contributions too.

lewisweller Member

lewisweller

Posted
Posted
11 hours ago, 911nick said:

Lewis' diagnosis was spot on. I installed the new box, and everything works like it should! This repair only cost me $50. Lewis, you really saved my bacon. Ekstroemtj, I appreciate your contributions too.

Where did you get the replacement module from and what software did you use to program it? What about programming the keys? 

My check tail light warning is starting to get tiring now, luckily I don't drive much at night. 

It's time I think to spend some more cash and fix this one. 

911nick Member

911nick

Posted
  • Author
Posted

Lewis, I found the module on ebay. The item was located within my area. I called the business, and it turned out that the owner lives near me. He was kind enough to delivery it to me that day on his way home. Since it is a used module, it came pre-progamed. How cool is that!

  • Upvote 1
lewisweller Member

lewisweller

Posted
Posted
25 minutes ago, 911nick said:

Lewis, I found the module on ebay. The item was located within my area. I called the business, and it turned out that the owner lives near me. He was kind enough to delivery it to me that day on his way home. Since it is a used module, it came pre-progamed. How cool is that!

Interesting, that means as long as the used module is the same model and spec options wise it's plug and play, great. Also mean the coding for keys is not required then or you wouldn't be up and runny at all. You have keyless entry correct? (kessy)

 

Sorted thanks for the info. 

 

I'm going to find a used module and swap out mine hopefully fix this check tail light bug. 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.