touareg

Are you getting all these errors when you try to start the car? Press Brake Pedal, and you pressed it? Tired of searching the internet, and being told it is just the wires in the drivers side failed, but no details?

Looks like a Christmas tree on the dash?

Ignition Lock Failure, Brake proportioning Warning, ABS light, Traction Control, Check Engine, Brake Light Flashing. Stuck in Park May or May not start.

I had water leaking in from the door to body grommet/hose. If your carpet is wet or damp, this is most likely the result of a small leak for a long time.





One person mention that relay 443 on top of the battery may be the culprit if you don't have a water problem.

So you have got all these on at once, car may or may not start. If you can get it to start, you are not stuck, but are in a limp mode. You can also put it in neutral for a tow.

You can remove the dual Allen wrench under the rubber mat in the bottom cubby.

Remove the two Allen screws, that you can see from that cubby towards the front of the car. Lift the center console surround, it snaps out from the back towards the front, with the front slotted in under the ash tray.

With a long tool, look in front of the shifter, you will see in my case, a 2009 Cayenne a red arm that moves the lock, press it gently to the left and you can now shift out of park.

WARNING: Your brake lights will not work and you can not leave 2nd (I think, gear) if you drive the car this way. I am not sure what else may not work from a lighting perspective.

Now if you want to fix it:

First, pull out the drivers and rear passenger mats if you have them on the Driver's side.

Behind the drivers seat, slide out the plastic beauty covers of the left and right rails.

Remove the two plastic covers, just in front of the Drivers seat base, and with a 5 point bit, remove both the screws that hold the seat in place. If you are having trouble with this, it is the same procedure to get at the battery.

Next, slide the seat all the way back, and then tilt the seat back forward.

Now, push the seat head rest with your hand back, the seat should now pivot on the rear hinges and tilt back.

Slide the forward with the power switch, and the seat will move out of your way even more. You can reverse all this later when you put the seat back, this method just avoids hitting the steering wheel.

Now, you do not need to open the battery box, just remove the nut from the ground cable, next to the seat bolt for the transmission tunnel, get a back and wrap it around the end of the cable, I used a rubber band for good measure. This will keep you from accidentally applying power.





Now the only hard part, you need to pry up the carpet, and it is a little tricky because we will not be removed the door sill.

Start from the B pillar, under the door sill, this will give you some flex in the carpet, when you try to remove the dead pedal section of the carpet.





Once you have it out from under the door sill, you can prop it up, I used a 32oz plastic cup.

Now is a good time to dry any water, etc from under there. My car would still start, so I ran the car on idle, high heat, full re-circ, and floor only for 3 hours.

Now we can open the flat plastic wire protector. Just release the tabs with a small screw driver, then fold it back, towards the door. You again may find tape, or a weight of some sort to hold it open.







So the cloth is multi layer and I assume was at some point sticky on the bundle. You can unwrap the end, right where it enters the flat black wire protector. That lets you peel back several strips of cloth that run parallel with the wires. Another pieces is wrapped around the wires circularly, no need to disturb that.





You will find 3 pairs of wires, in my case one was crimped and had a plastic protector. 2 were connected somehow, with cloth electric tape wrapped around the twisted pairs. One just pulled off and I had plastic wire stubs, the inside was corroded to copper dust!




Note the green copper wire, about 2 inches of it, turned to dust in the electrical wrap!



The other looked fine.

So the problem is two fold, 1 they are lousy connections, 2, they sit at the bottom of the bundle, right where water would pool and absorb into the black wrap. You could see the corrosion on the black wrap in my case, so I had a pretty good idea, plus when the car was on and I pressed that spot, more alarm dings flashed!





I pulled all three pairs of the crimped wires, and moved them further up in the bundle, under the dead petal, so I could get slack and re-locate them later.





The bad red wires I striped back 1 inch, clipped the corrosion off, butt joined and soldered them with shrink tube, then folded over and wrapped in electrical tape.








The good black wire, I still pulled the electrical tape, shrink tubed it, folded over the remaining shrink tube, and electrical taped it, with zip tie to hold the tape down.





Finally I tucked all 3 wires on the top of the bundle, under the factory zip tie behind the dead pedal, and zip tied them to the bundle. This way if water gets in I have to have 4 or 5 inches of water for it to sit there for a long time and repeat what happened.





I was able to nicely put the fabric electrical tape together, zip tie it in several places, and tuck it all back in.



Pushed the carpet back in, connected the battery, car started no problem few errors, but all cleared except the check engine light after a short drive and putting my seat back in.

This really should be a recall.

Took me about 1.5 - 2 hours to complete.

CAVU

Wow! Nice find.

How did you know to look into the wire bundle or was it a logical place to start based upon all of the moisture.

Great write up!

touareg

Well, I recently found the door leak, cleaned that up and 3 days later I started having this problem.

Googled around a bit, but nobody really had much detail on it, just "it is the wire harness"

It was really only damp a little bit under there. And over 2 days the error came and went.

Honestly I am surprised it conducted at all, as nothing was left of the bare wire on one and a 1mm on the other.

After the car became a brick, I was able to "squeeze" the wire, and cause error dings to trigger.

Also logic dictates I doubt 5 modules would go bad at once.

touareg

This makes an interesting gander, and explains why you get all those module errors, assuming the blue line was the one interrupted:

touareg

Happy to report, things are still 100% as was before the disaster! I did so some more research some of those wires are data lines for CAN and that does explain the errors. As you can see in the chart above, some modules have dual NICs so to speak and are accessible on the systems bus from two different locations.

The low speed bus can be kept powered on when car is off, to allow basic functions, but switches over to the high speed bus when the car is running and power sipping is not a concern.

MM951

Great post! Thanks!

matt_o_70

Hi - I am trying to help a local Cayenne owner and this thread seems a similar situation.. The car is fairly new to him and prior to harness repairs he tells me he had many lights on the dash..

Currently his engine will not run. Starter will engage and crank for a few seconds before the VME/ECU will cut the starter off (key still held in start position). The only way engine will run is to provide alternative fuel into intake (spray can). I am told that fuel pressure was verified at fuel rail (with gauge). So I presume that the injectors are not getting activated.

He has looked at both wire harnesses under the driver and passenger side carpets and recently repaired some corroded or broken wires. the car ran for a few days after the repairs and I am told that this improved a stutter on acceleration condition. He has also replaced both batteries (early car). we have cleared the faults - there were many - I assume from before the wire harness repairs.

I am looking for any information or documentation to help diagnose - Why injectors would not be pulsing? I am assuming that IF the VME was deliberately disabling the engine from running there would be a fault message or error on the dash display -perhaps this is not a good assumption?

I intend to verify fuel pressure and try to read if injectors are pulsing.. Anyone seen a no start condition that relates to wire harness under carpet in the past?

Matt

touareg

When I was researching this problem, I read somewhere, so this in anecdotal, that those wires are can-bus related, so that is why they caused so many issues.

Other things I think I saw mentioned is people looked at the wires, they looked fine (or repaired just one), but they later had to go back, remove the covering tape and re-solder. My advice, if your friend didn't do the repair, and you didn't do it, take it apart to be 100% sure the wires are really repaired properly, not just crimped, or worse, twisted together and duct taped.

I actually removed the electrical tape from the second wire, the other wire had a clear wire nut crimp job, so I could visually see it was fine.

touareg

Only problem I have left, if I hook up my durametric or bluetooth reader, the car throws errors, or wont accelerate properly. Not sure if this is my cable or something else...

Shawn Stanford

I had the exact same problem and I followed Touareg's instructions and my P!g is now back among the living.

The moral of the story is to clean out those drain plugs!

JAGMAN1

I do it yearly. A bit of a pain to drop the fender liner, since reinstalling it is the hardest job known to man.

I've also removed the large rubber Grommets. Far less debris collects. But I still check yearly.

Shawn Stanford

I didn't drop the liner. I pulled the wheel, undid four screws, and jammed my arm all the way up in there to reach it.

CTTS520

What are the drain plugs you're talking about and where are they located? Will you please post a DIY link for the cleaning procedure? Thanks.

Shawn Stanford

This video shows the easy way to get at them:
This one shows what they look like:

deilenberger

This one is pretty interesting - doing it from up top.


Skip ahead to about 1 minute.

Have to see if that works on my 958 CTT

REPORT BACK: Not quite the same:

o - Port (left) side there is a hole WAY down below the level of the brake booster - between the booster and the e-box. Found a 24" tie-wrap - poked it around and through the hole about 8" - nothing came out underneath, and the end came out dry. I kind of wonder if that was the drain hole and someone already removed the rubber goober that plugs up. I could see some scattered organic matter (leaves, nuts) in that area - washes down from the windshield. Got as much out as I could - but really need a 2 foot long pair of tweezers to get it all out. Airgun on my compressor blew some out, but some remains. The cover over the ebox-brake area on the left side sure looks like the wiper arm inside will hit the bottom of it. But apparently - it doesn't. It is a PITA to get back in place.

o - Starboard (right) side is completely different from video. Has a catch-tray for any water that gets through the heater intake grille. The catch-tray acts like it should lift right out - but it doesn't. Something is keeping the left side of it from releasing. I could move it enough to see under it - and all way dry as far down as I could see. I poked the long tie-wrap down in that area - and it went down about a foot below where I could see - and came up dry. Couldn't actually see a drain hole - so no idea if the goober is still in place.

I think I'll wait until the temps get over 30F to take a better look at things, perhaps outside.