I’ve been having 4WD faults on my 955. I scanned and it threw up a 02053 code. I changed the switch on the centre console and tested the transfer box servo motor. Is it possible the control module under the seat has failed and is worth changing out? Or does anyone have any other familiar problems they’ve had. Any help would be much appreciated
thanks

 

Porsche has a TSB from back in the day on swapping out the Transfer box's on for replacing the Transfer box control unit when getting a clunk on '03-'06 Cayenne's, and another for certain faults, 2033, 2039, 2041, 2042, in this case they say to replace the Servo motor and the Control unit. So in neither one of these cases do they mention fault code 2053. May just clear the codes and see if and when the fault comes back? How long has it been since the Transfer case itself was serviced?

 

the fault comes on instantly on startup. I cleared the codes but didn’t clear at all. Was back on instantly

 

Standard questions, especially for a Cayenne. How many miles/Kilometers on it and how old is your battery? I am leaning more towards your Control module as you first thought. Also wondering about your stepper motor. When you get the fault are the differential/low range lights on the center console On or flashing? Have you tried to engage low range? Just that Porsche had issues with early stepper motors and since yours is a '05 I think I'd also look on Ebay or somewhere for a little newer Stepper motor. Sometimes in the Ebay pics of a stepper motor you can see the label and date. The Stepper motors for the Touaregs and Q7's of about the same years work too as if you look at their ads you will see the same manufacturers part # on them. I think they "Porsche" used that same stepper motor up through '10 with a couple of updates. I've got a '06 CTTS and mine somehow still works but I did find a '08 stepper motor that I purchased for a spare. I'm sure they still sell newly manufactured units but I haven't looked up the cost in years.

 

The very latest part # is PAB-341-601, previous part # was 95562460101. Looks like Porsche changed their standard part # naming convention, maybe it has to do with the age of our vehicles? In the states here, Porsche wants over $1200 for a new one, but if I go to some aftermarket suppliers, I can get the same part by the same manufacturer for under $500, that is for the Stepper motor. I think Ebay is the best place to look for the Transfer case control module too.
https://rennlist.com/forums/cayenne-...957-owner.html
The above thread has a link to the TSB with some part #'s.
The latest control part # is 955-618-025-03, according to Porsche it fits all Cayenne's from '03 to '10. The other number to search for on the unit and sometimes listed on sites like Ebay is the one in the TSB, 0AD.927.755.BT

 

there’s 80k kilometres on my cayenne and the battery is 4 days old. I pulled up the passenger seat carpet (RHD) and was soaking wet and some of the spliced wires corroded so checked the driver side and was soaking wet too. Pulled out the seat and is currently drying out now. The harness is also wet so going to open it and see if anything is corroded to. Will purchase a new control module and servo motor too

hopefully will be okay after!

 

Not good news but at least you found a likely culprit. There are multiple old post about the wet carpet and faults. My Cayenne always is parked in a garage so I don't have issues with leaves and stuff clogging the drains. Some of the posts talk about cleaning the sunroof drains as well as the cowl drains. Some of the drains are like thin walled plastic hoses with pinched ends. The idea is that the weight of the water will open the pinched end enough for it to flow through but when you get any kind of leaf or other debri it ends up clogging it and eventually builds up enough that even the water no longer flows through them.