'04 CS Electrical Gremlins - rear lights, liftgate, moonroof, subw

[macayennes]

Hello all,

Well, the ridiculous electrical anomalies have hit me in a big way and I would really appreciate some advice.

On two occasions prior to this week, my rear fog lights and/or brake lights have come on by themselves and flickered on and off uncontrollably - I was able to remove the fog light fuse and this stopped the issue, reinserted it and all has been fine for months.

A few weeks after that, I came out to the car and there was a random thumping - turned out to be the subwoofer and I removed the fuse and have been unable to keep it in, because it randomly hums and thumps.

This week, my rear brake lights (all three) were on and at time flickering. I tried removing all fuses for the lights and the lights stayed on. I then drove the CS and the rear liftgate window latch started popping open continously. Menawhile, I'm getting a ton of warning messages, including one that my rear tire carrier is open - I don't have the rear tire carrier.

Came home, couldn't open the lift gate or get the lights out. Drove the car again, rear brake lights went out, but the license plate lights stayed on. Drove the car again and the moonroof opened, but wouldn't close, the rear backuplights stayed on and the brake lights flickered.

Next day, all of the rear lights are out, however, I can't operate the moonroof, can't open the liftgate or liftgate glass and can't set the alarm. Also, when unlocking the doors with the central locking button on the armrest, it cycles a few times (instead of once).

I'm at a complete loss - especially when I can remove all pertinent fuses and the lights/devices they control still work (or have them in and don't work).

Any suggestions would be appreciated - I fear a trip to the dealer - not exactly what I was hoping for since I've lost my job and have a newborn. Any thoughts on estimated cost for the dealer to pull the codes?

Thanks in advance!

Mike

[Loren]

How old is your battery?

One sure sign of a failing battery (on Cayennes') is miscellaneous electrical problems.

If your battery is over 4 years old I would start there.

[wvicary]

What year is your Cayenne? Some of the early ones had two batteries and as Loren suggested that is the first place to start.

[macayennes]

What year is your Cayenne? Some of the early ones had two batteries and as Loren suggested that is the first place to start.

Thanks Loren and wvicary - I'm not sure of the age of the battery, (it's and '04 and I've checked under the sub, so I only have one battery). I just went out and bought one tonight and I'll give it a shot - that is, if I can find a M10 triple sq spline bit to lift the seat (didn't have any luck at Auto Zone, Pep Boys or Lowes and Sears was closed by the time I got there). Is there one in the tool kit? --I would think there would be, but I can't open the liftgate. Before I unhook the baby seat and empty the cargo area from the rear seat, could anyone let me know if there is a M10 wrench in the tool kit?

Thanks for your help!

Mike

[wvicary]

I have never seen it included in the tool kits.

[macayennes]

I have never seen it included in the tool kits.

OK. Thanks. I'll pick one up tomorrow.

Mike

[macayennes]

Hello all,

Well I changed the battery and the problems still persist, but have changed a bit. I would appreciate any advice or direction.

- Lost "Comfort" selection from the vehicle setting menu (no alarm, door unlock choices, etc)

- Moonroof will not open

- Alarm does not function at all (no LEDs, key fob functions)

- Tail lights will not operate (only go on/off randomly)

- Liftgate and glass will not open

- Fuel door won't open

- Rear fog lights won't operate

- One touch open/close function doesn't work (I've followed the resetting procedure several times without luck)

- Radio doesn't always shut off when I exit

- There are NO warning lights or messages

Any advice would truly be appreciated. Right now, I can only drive during daylight since the taillights are unreliable and who know when the brake lights are going to stop working (which they've done before. I'm stuck removing the ground wire every time I park the CS to avoid potential battery drain - not exactly convenient.

Would the Durametric reader be of any benefit for this (would it read lighting faults, or would there even be any since there are no warning messages?) or is this a PIWIS only problem.

Could this be a central lighting control module issue only (even with losing "Comfort" selection, Moonroof, etc)?

Any recommendations for a quality repair facility in the MA/RI area or dealer service recommendations? And I really hate to ask, but any thoughts on the range of cost for this if I have to go to the dealer?

Thank you in advance!

Mike

[wvicary]

You need to access all the modules,record any fault codes and clear them all. That should reset the systems. You'll then need to rescan the modules and address any codes you find at that time. Durametric is highly recommended.