wingless

What is difficult, pull off the cover and remove the ground strap?

Okay, the DME needs to "readapt" the idle and mixture, the tyre pressure is temporarily gone, the steering angle sensor needs to be reset, the roof needs to be reset, the windows need to be reset and the clock needs to be reset.

BTW, the ground strap torque is 15 ft-lbs.

LVDell

What are you referring to as the "ground strap"???

But I do agree, the list of items that need to be corrected when reconnecting the battery is just over the top. Why can't things be easy like they are on the 911??? This has become more comincal than anything at this point. Yes I was frustrated and often mad but now? just have to laugh!!!!!!!!!!!!!!!

wingless

The Cayenne is built and shipped with a large battery disconnect switch, accessed at the cover, under the driver's seat, at the front. That switch is removed, recycled and reused. That switch breaks the battery ground lead, to the chassis. That ground lead is the "ground strap".

Examine the TSB for removing and returning the switch for more information, pictures too.

You didn't remove the driver's seat, did you?

The seat screws are supposed to be replaced and not reused. IMO, it is acceptable to reuse these, if Loctite is reapplied.

LVDell

I did NOT remove the seat, just removed the front 2 bolts and tilted back as the manual states. Then just disconnected the battery from the battery cables (neg and pos).

I am going to reuse the bolts but apply loctite.

wingless

It is likely that just pulling off that lower cover and removing the ground strap would have provided the desired results.

LVDell

Probably. But better safe than sorry with these things. Total battery disconnect is what I call safe

356driver

I didn't disconnect the battery because the car has to be programmed to accept the tow control unit. This can only be done at the dealer so I simply left the tow control unit harness disconnected. When I took it to the dealer for service I had them plug the tow control unit in before they programmed it. Disconnecting the battery was their problem.

LVDell

Too late. Battery disconnected. I am just going to swing by the dealer anyway after the install to have it checked out my by SA. He is a really great guy and takes good care of me. Shouldn't be a problem at all (if there even is one).

wingless

Disconnecting one battery lead provides the same results as disconnecting two.

It is possible that the vehicle may complain, in some way, to the addition of the tow module, prior to the dealership programming the vehicle to permit proper functionality. If so, it would be useful to know what happens.

So, once this is installed, after the steering, windows, roof, clock, idle rpm and fuel mixture are properly reset, please observe if the vehicle complains and report on those results, prior to the dealership enabling that module.

LVDell

Report (if anything) to the dealer before they program? I guess I don't follow what you mean by "report".

Thanks for your input

356driver

Most cars are one big computer network. This is not particular to Porsche. All cars are like this. Even an economy car has more than 20 distinct computers spread throughout.

Diagnostic information between all of your computers flows through the CAN bus and is collected in memory. The dealer plugs diagnostic equipment into the car's data port and diagnostics are uploaded. In your case a bunch of faults are likely to be reported because your various computers went dead when you disconnected the battery.

To avoid confusion and alarm, you should tell your dealer what you did, what messages you saw on your display, and how you might have resolved them. Personally I would leave the tow module disconnected until you get to the dealer, because your car does not know it belongs there, and it is likely to display a bunch of annoying alarms. Have the dealer connect it and configure it into your car's system using their diagnostic tools.

Personally, I think we're getting to the point where Ctr, Alt and Del keys ought to be added to the instrument cluster.

LVDell

Isn't that so true!

I'll take your advice on the install. I'll leave it disconnected and let them "plug and program".

Thanks!

LVDell

....and the brake controller? Should I leave that disconnected as well?

ltc

Hmmn, battery under the seat.....what's next.......oh, I don't know, how about MOST DSP audio amplifier under the seat

LVDell

Well, I decided to call my SA at the dealer which by the way is the type of SA every P-Car owner would want. This guy really takes care of me. Anyway, I called him and asked him about the battery disconnect and the control unit for the towing sytstem and he said just connect everything up and it should be just fine. No need to program since it is a 2005. The program was required for the 03-04 cars. Well, I completed the ENTIRE install, hooked everything back up and VOILA!!! Everything is perfect. All my seat memories are still there, my garage remote still is programmed, the seats kept their locations, and the Pepper didn't freak out as most thought about the addition of a towing control unit.

No need for a trip to the dealer and now I can't wait to tow!!!!