bobinyelm

Curious- Did it have any DTC codes you could pull before you looked and saw that it was physically toasted?

I started this "project" with about a dozen DTCs that plagued my new-to-me '04 Cayenne (that has turned out to actually be a 2003 according to the build date). I replaced an after-cat O2 sensor to try to cure a "Cat Low Efficiency" DTC (P0431), so I will assume on that one is a genuinely tired Cat at 136k miles. The other codes have all disappeared with a new Group 95 Battery,/H9 (vs the Group 49/H8 the last owner installed and which was at only around 11v ignition ON and not running) except for a level sensor I am awaiting a replacement I ordered. The LAST "BIGGIES" are DTCs for the Transfer Case, DTCs for "Power Supply" and "Grounds" for Transfer Box Servo Motor DTCs 2040 and 2041. I pulled ALL fuses and checked for corrosion and put them back, and checked for voltage at BOTH sides of every fuse. No problems. All wiring harnesses look great-no signs of physical damage or corrosion anywhere I surrender... Anyone offer a FINAL Hail Mary before going to the Porsche Dealer where they have a Test Box for the transfer system?

Thanks- Hopefully tomorrow evening I'll have some positive news.

Accessed the battery, and it looks like it was put in yesterday (perfectly clean) but I will be replacing the "Duracell" Group 49/H8 with a new Interstate tomorrow. I'll see what happens then-

2004 Turbo, 130k miles I have faults saying the transfer case servo motor is not receiving power (nor does it have a ground). (Codes 2040 and 2041) The portion of the Transfer Case/Height Control control box that relates to the drive system (left half) is also not illuminated as is the portion that controls the ride height,. leading me to wonder if the lack of illumination AND lack of control over the T-Case is power related. I cannot find any fuse labeled as if it might feed the transfer case module or servo, but it makes sense that this circuit would be fuse-protected. Anyone know how/from where the T-Case gets its electrical power? The harness is plugged into the motor and shows no physical damage and no corrosion on the pins. I get no "bump" or sensation (or lighted representation of the drive line on the control panel) indicating I am actually engaging 4WD when moving the control, which certainly would fit if the system is unpowered. I also have a low battery (around 11v) w/ the engine not running (it's 13.8-14v w/ the engine running), so will be changing the battery tomorrow in case it's a battery problem.

Thanks, and yes, you are of course correct on the model. Mine is "simply" a Turbo and not a Turbo S. Frankly, I looked a several cars before buying mine, and a few were Turbo S cars that were (1) More expensive, and (2) in need of more maintenance (ratty interiors/looked tired). I examined the door jam sticker after reading your reply and was somewhat surprised to find my car was manufactured 05/03, making it a 2003 model, though it is titled as a 2004 on the paperwork. The 11.4 value was with the ignition ON, but the vehicle not running. I didn't measure cranking volts, but it cranks fine (normal crank rpm). It rises to 13.8-14.0 running/charging. I assume the height sensors are Hall Effect units that normally shouldn't go bad? Since I am sure my scanner (Autel MaxiDAS 708) doesn't have that calibration ability, it sounds like that I need a better scanner or a visit to the dealer to calibrate (or replace the part if that will fix it). I found my scanner does adaptations for many makes, including VW, but NOT on Porsche, too. The local Porsche dealer quoted $500 just for the height sensor alone, I suspect that the dealer option will be prohibitively expensive, but the dealer said the units are indeed VW units (7L0 616 571), but that Porsche testes and certifies every VW part they use in their cars as most VW parts off-the-shelf don't meet Porsche quality standards and are returned to VW, so they have to charge more for them. On the "list" of "To Dos" it's quite a bit longer, with codes for several systems (mostly servo issues for footwell flap, central vents, circulation flap), Rain Sensor, Footwell Light Potentiometer, Park Assist Module, Immobilizer, door locking system, and a few more. The "Biggies" were the Post Cat O2 and the Inop Transfer case (No ground or Power for the Servo Motor). Thanks

I guess I'll pull the seat and check on the battery today then. 11.4 volts before engine start is super low even though it pops to 13.8-14.0 v when the alternator comes online. I do notice that unlike the suspension height control, where the switch pointers are illuminated, the transfer case control is completely dark with no lights at all. Just curious, though. Is this likely because the system is actually unpowered, as the DTCs imply it is (ie, no power or ground)?

I am new to my '04 Turbo S and the car has some deferred maintenance issues. I want to do as much myself as I can, but there are some things I would like to have done by a competent shop to start with due to Check Eng Lights and rough running issues. I was wondering if there are "stickies" or files where "reasonable" cost estimates might be found? I did a search to no avail. I am getting misfire codes (random cylinders) and acceleration is not smooth, and I suspect the spark plugs have over 100k on them, so (1)how much should I expect to pay for new plugs installed. (2) Also the after-cat on Bank 2 shows a MIL code, so will have the After-Cat O2 Sensor changed. (3) I also have a right rear self-leveling sensor code, and the instrument panel mentions a malfunction for that system. The dea;ler quopted $435 for the sensor, but it's a special-order part they do not stock. (4) The battery light is on (little orange rectangular symbol in speedometer) and the scan tool showed 11.4 volts before engine start, so I am told that the battery should be changed (though the car starts fine). The manual says the seat bolts must be renewed when the battery is inspected or changed. Given the cost/compexity of servicing teh battery, what brand would be the best for longest life and zero maintenance during its entire life? What would be a reasonable sum to pay to have a new battery installed, and DO you really need to go to a shop where they can replace the seat bolts with new factory bolts? The O2 sensor looks like a tough job (the one shop I consulted mentioned dropping the exhaust and replacing ALL of of the O2 sensors at once for a price I hesitate to mention in mixed company. I was hoping to just reach up and change the one sensor, but the steering shaft is badly in the way. Thanks, Bob

This is my first post here since acquiring a 2004 Turbo S. It has deferred maintenance, so I purchased a decent Scanner (Autel MaxiDas 708) to start sorting things out. First order is the transfer case, which shows DTC 2041 (Ground supply for transfer box servo motor) and DTC 2040 (Power Supply for transfer box servo motor). I was hoping it would be something simple, like damaged wiring harness at the servo on the transfer case from off-road debris (former owner used the vehicle off-road to go camping/fishing), but the harness was perfect. I couldn't find any fuses for the system either, unless the system is fed from a fuse w/ a different name. I had one DTC (Transfer case switching error), but it WOULD reset, though the other first ones will NOT indicating the condition exists currently. I am sure if I drove the car, this one would reappear, of course. I tried a Search, but it wasn't on-point. I am hoping it's something relatively simple since I downloaded the troubleshoting manual for the T-Case and it alone is 65 pages! (And uses a test box only dealerships are said to have) Any suggestions welcome. Thanks, Bob