Rick

Two questions/issues:

1. I know I'm not the first to experience this - the Check Trailer Light Warning comes on whenever the Right blinker is on and you apply brakes. I don't think there's anything unsafe or seriously wrong but it's a bit irritating. I just got back from the dealer and they can't figure anything out. I think all they actually did was verify the trailer connections. Does anyone know what the fix actually is so that I can advise my dealer?

2. Also, is there any kind of update for the MFD? It's my understanding that it should return to whatever function it was left in - however, mine returns to a random selection but most often returns to the MPG display; I'd like it to return to whatever I showed last since that is what the manual says it should do.

Thanks much.

Rick

ltc

Rick,
I have asked my dealer about #2, Porsche has no official TSB nor position on the matter. My Cayenne loaners always stay where you left them.
If you search for the previous thread on this, it seems to be all over the place, some do, some don't. I have just resigned myself to living with it (FWIW, mine always defaults to AVG MPH)

Periokid

I think that Kevin had the same issue with his trailer. He said there was an update to the control module.

My MFD always goes to ave MPH at start up.

oscarb57

There is definitely a fix for the trailer light message. They're replacing my control module (in the rear of the truck) next week.

Kevin M.

Oscar is correct, the fix is to relpace the module to a new updated one. That solved the annoying problem

Rick

Kevin/Oscar - I'll talk to my service guy this week; do you have a part number for the control module or will they know what I need if I tell them I need the control module replaced?

Thanks much.

Kevin M.

Rick, they will know... I would get it for you but my service order is still open so I didn't get any paperwork. If your service guy is clueless let me know I'll call my dealer to get the part #

Rick

My Cayenne S goes back into the dealer on Friday to have the trailer module replaced which should solve one of the problems.

I had the chance to talk to the Porsche rep about the MFD issue - here is what he said. Since Porsche eliminated the dual battery configuration to accomodate the spare tire they had to reduce/eliminate as many "parasitic" electrical devices as possible. Evidently, having the MFD retain the last selection & value consumed a reasonable amount so that feature has been eliminated. New owners manuals are now being printed that will indiated that the MFD will return to Avg MPH.

Here's something that some of you might find interesting...I use my Cayenne to tow a race prepared 944 Turbo S; we ran the car this weekend at Putnam Park (a 1.766 mile road course near Indianapolis). I was ablet to turn consistent low 1:20 to 1:22 lap times in the race car - I took the Cayenne S out during the lunch hour and turned a 1:29 on my 4th lap and it felt great.

I'll admit the car has had a few minor glitches but it's a great car!!

wingless

This topic has the control unit part number.

http://www.renntech.org/forums/index.php?showtopic=1829

mudman2

Wingless

Do you know if the control unit is fitted to all cars ? even though mine does not have a P Hitch I see what I think is the control unit (looks like it from the tech manual).

Mike

wingless

I'll check, but given that Porsche won't even run a single wire that is not required I think we can both guess the answer.

mudman2

Pretty sure now that the box I am looking at is something to do with the changer

wingless

The electronic trailer lamp control module is not present on vehicles without the hitch. Also, the wiring to the 7-pin connector and some wiring to the module are not present.

However, the 4-pin electric brake connector, near the parking brake lever, exists on all U.S. vehicles. Most of the CAN bus connector wiring, to the electronic trailer lamp control module exists, on the Cayenne, built for the U.S. and built for the rest of the world.

mudman2

Wingless, I do not believe that the 4 wire harness is active based on my brake controller instal today, its just present.

wingless

Is there a unused connector, near where the factory electronic lamp control module would be located, that has the blue brake wire from under the dash?

The harness from the 7-pin trailer connector would go there and to the electronic lamp control module.