tpwierimaa

Greetings -

This is my first post so please forgive any etiquette errors. I am REAL new here.

My wife owns an 08 Cayenne GTS. It is starting to act up and frankly I could use a little help as I am unfamiliar with porsche systems.

The symptoms we have are:

1. The sport mode (sport exhaust?) is stuck on. The light on the button is on and pressing the button does nothing.
2. The traction control module next to the sport button is lit for all four settings. Toggling the switch up and down does nothing to the lights.
3. There are errors I think which are important (P0455 and P2181). I am not sure how these relate, but I am amost certain they do.


How would I go about trouble shooting this? is there a wiki or a definitive thread?

I am sorry if this is a common problem and I am just adding to the heap - I am not even sure what terms to search for on the forum to fix this issue.

Thanks for any and all help.

TomF

Welcome and sorry for your troubles...

Start with testing the battery. Lots of strange symptoms occur when a Cayenne's battery starts to fail. Also check for any moisture underneath the front carpets. This is indicative of clogged roof drains and can cause tons of electrical gremlins.

There is a tremendous amount of institutional knowledge here- please don't hesitate to ask questions after you have tried a search.

Cheers,
Tom

tpwierimaa

Thanks Tom.

The battery is new. I replaced that about 4 months ago.

I am not sure about the roof drains, but there is no moisture in the cabin. The entire cabin is bone dry.

Noob question here - is the "sport" button synonymous with Sport exhaust? What does the traction indicator to the left of that do? Or what is it supposed to do? it is lit up like a Christmas tree right now.

Rossi

P2181 is common issue, your thermostat is stuck in open position or just not closing fully.

https://rennlist.com/forums/cayenne-...at-09-gts.html

Libast

1. and 3. might be related to a leak with the vacuum pump. I have the same code and my sport exhaust is stuck "on", but the light is not lit.

The left tree is not traction control, but the rocker switch for the off road modes. If all these lights are lit, that entire module (rocker switches etc) might be going or gone.

Burnt McGurnt

Just a hunch but I would check to see that the vacuum lines going to the tailpipes are in tact.

Any problems with the air suspension? There's a mode that locks out the height adjustment controls, but there would be a message saying so at startup in the driver's gauge pod display.

tpwierimaa

No other issues other than the christmas tree and the sport button lit up.

I can check the vacuum, is there a process or a wiki how to do this? I assume there are some gotcha's - all things porche seem to have a gotcha.

What does the traction being all lit up mean? Does it mean I am stuck in 4 wheel drive?

EDIT:

Tom, thanks for the P2181. Looks like I will be tearing into that shortly.

Also, how would I check the rocker switch module? I suppose it could be a switch? Or is this all run off the same vacuum line? They have to be related - they happened at the same time.

tpwierimaa

Here is the offending items. These two controls will not change.

If someone could even point me in the direction of what they are called I would appreciate it. I havent the foggiest idea how to trouble shoot them.

v10rick

P0455 and the PSE issue are associated.

The EVAP pump supplies vacuum to the exhaust flapper valves and the emissions system.
You can measure the vacuum at the valves, which are mounted just behind each exhaust outlet. I measured 20" with a new pump at that location. No or low vacuum is the reason for always active PSE. Vacuum is required to disable PSE.

If the Sport Mode light is always active I suspect there will be no vacuum at the exhaust outlets. This should not cause a P0455 code, unless there is a leak in the lines to the sport exhaust valves.

Any chance a drink was spilled onto the control console?

uphoto

Long shot here but what are the odds that both of those switches are stuck on at the same time?

Those are right next to the sad things that Porsche calls cup holders, could a liquid spill cause those to short out or act up? Maybe taking that apart and see if there is corrosion?

tpwierimaa

I was thinking the same thing. So strange that they both go. Can a fuse do this? Where would I find the fuse for that?

The buttons click and do not stick. And I know they have power since they are both lit up.

I will climb under the car this weekend and check the vacuum at the rear to see how it looks. I assume I can just attach a vacuum pump at the rear and it should hold a certain reading? Anyone know that reading off hand?

tpwierimaa

and there is my answer. Yall are clairvoyant.

I dont think a drink was spilled - but I cant guarantee it. Would the P0455 code affect the traction control (what is that thing called?..) on the left of the sport button?

J'sWorld

It's not traction control. Its ultra easy to get an owners manual so you can get familiar with your vehicles controls. I am clairvoyant, but you don't want to know what my sixth sense is telling me.

tpwierimaa

So now I am stumped. According to the manual (thank you Jsworld) the program is stuck on D with the rear differential locked. I simply see nothing else on this issue. There are no fault codes and I cant find anything on the internet about this system. I cannot even find the system in the parts fiche.

The only thing I found was a control module - PO-95561802503. Is this something that goes bad?

Burnt McGurnt

I dont know the exact name but it's the 4wd system selector. FYI the vehicle is full time AWD but there is a locking center differential and a low range mode that you can engage with that toggle switch. As for traction control, the vehicle has PSM switch on the dash.

Regarding your other fault code, check your gas cap and gasket first. Something in the evap emissions system is disconnected, broken, or open. Not just a little leaky.

*I'm 100% copying the below from another's post, but I don't know how i would quote that here.*

----------------
P0455 Evaporative Emission System Leak Detected (large leak)

Possible cause of fault

- Tank cap not tightened correctly, faulty or missing

- Mechanical fault in EVAP canister purge valve (does not close fully)

- Leakage diagnosis pump leaking internally (membrane) or externally

- Mechanical fault in EVAP canister shutoff valve (does not close fully when power is supplied)

- EVAP canister shutoff valve connections leaking

- Tank system (including pipes) leaking

Check your gas cap and seal.