Dear Members

i would like to ask for your help please.
just bought another Cayenne Turbo. Should be a car for Winter. Already old Ager but in a really good condition. I am located in Germany
story / problem is:
I don’t know how it is in the states, but here you have to bring your car every 2 years foe a technical check. You need to get a sticker for 2 years to be allowed to drive the car.

today I went there. Everything ok but...
car failed to pass the emission test.
i even was afraid something in this direction could be. Didn’t drive a lot but fuel consumption is much much higher comparing with my Turbo S.

what can be wrong?
found out the passenger side fuel pump is dead. Could this be the reason?

any advice is very welcome. What’s causing the wrong fuel/ air mixture?

thank you very much in advance

 

I am afraid you probably won't get many responses without providing more information. It is impossible to diagnose the issue based on what you wrote. A good place to start would be to scan the engine controller for fault codes and post the results here.

 

Because the Cayenne has catalytic converters and oxygen sensors before and after the catalytic converters and an engine computer, it would be very difficult for a Cayenne to fail an emissions test without a "Check Engine Light" (some people say CEL instead of check engine light)... this is the yellow or red light in the instrument panel that looks like the outline of an engine. All cars now have a "diagnostic port" or OBDII or OBD2 (on-board diagnostic) port. You can get a small device for about 10 Euros (OBDII Code Reader) that will connect to a mobile phone with Bluetooth and tell you any diagnostic codes that are stored in the computer. That is the best place to start (and the cheapest) if you did not receive any explanation for the emission test failure... did you receive any information (papers) from the test about the reason for the emissions failure? There must be a reason like too much carbon monoxide, or too much hydrocarbon (fuel that was not burned) in the exhaust or a leak in the vapor recovery system---but all those problems cause a Check Engine Light.

What are you going to do about this problem? Fix it yourself or take it to a shop and have them fix it? If Porsche dealers in Germany are like Porsche dealers in the US, labor is US$200 per hour or more ($250 per hour in California), and a part that is US$100 for a Volkswagen Toureg from a VW dealer... same part for a Cayenne from a Porsche dealer is US$300. Repairs from independent shops can be much less expensive than Porsche dealer prices. Many of the things that break on Cayennes are the same parts that are used in the Toureg and the Q7 Audi.

You did not say what kind of Cayenne it is... 2003-2007 or 2008-2010 (if it is a newer Cayenne, this is not the correct forum for you to ask your question). There are 2 fuel pumps... low pressure and high pressure. The vehicle also has a "gasoline vapor recovery system" that can leak and that would also cause an emissions failure, but that would create a Check Engine Light on the instrument panel. We need more information about the reason for the emissions test fail.

 

Thank you guys for your input.
I am a little bit familiar with these cars and I am doing a lot by myself . As much as possible let’s say.

i am having a Turbo S and another Turbo which i just brought.

The car we talk about is the Turbo with 450 PS. Model 2004
i have checked the codes when I bought it with my OBD device. Stupid me I did it only with engine not running.

the code with the Fuel pump of course only showing up with running engine.

there is no other code
there is no Check Engine Light.

i can add the test protocol but of course it’s German language.

i have to say thank you very much to you for supporting me finding the reason of the problem

 

P0230 indicates a problem with the #1 fuel pump relay output circuit. First thing I would check are the fuel pump fuses in the fuse panel under the hood near the windshield on the driver's side. The fuel pump fuses are 13 and 14.

 

The fuses and relays I have checked . Every ok. The pump is dead. When I pull 14 the car is still running. When pulling 13 the car is died after some seconds.

 

The car will revert to one fuel pump or the other depending on the level of the fuel in the tank. The idea here is to balance the wear on the two pumps. During high engine load conditions, both pumps are activated.

It is not unusual that pulling one of the fuses while it's running kills the engine. This doesn't mean a pump is dead necessarily. If I recall correctly, the system will default to the other pump if you pull the fuse for one pump but this needs to be done before starting the engine. IOW, you should be able to start and run the engine with either fuse 13 or 14 pulled but not both, of course. Someone here can correct me if I'm wrong.

You could also try swapping the fuel pump relays. They are the ones marked 404 in the same fuse box as the pump fuses. See if the fault code follows the relay. I can't find much on the specifics of the P0230 fault code but I get the impression that it's checking the voltage post relay going to the pump. If that is true and the fuse hasn't blown then it kind of sounds like a bad relay (or some wiring issue).

 

Thank you for writing!

you are right, the car runs on one pump if necessary. My car is doing exactly this.

with both fuses in. The car is going to die after some seconds

with only fuse 13 in - the car is running

i swapped the relays already- no change


i Open the fuel tank today. Gauge on the display was showing 30 km to drive. So it was almost empty .
Not very difficult to open. Left side was almost bone dry. Little bit confusing all the fuel lines. For my suppose, the pump inside looks different to the new one.

 

inside is a pump which looks different from the new one i had already .

the new one is a VDO which according to PELICAN is matching the car.

please check the pictures .

the old one has a edge and is not plain on top / red marks





the old one has a hose connection / red mark - which the new one dont have

i am confused.

 

the left pump inside looks the same like the one which is displayed on the DIY write up from a friendly Rennlist Member.


https://rennlist.com/forums/cayenne-...p-routing.html

 

make sure that hairy technician wears gloves and mask at install

 

Would it be possible using a OBD Tool finding out, if the problem is related to the oxygen sensors or to the catalytic converters?

 

If there is a code, the Check Engine Light should be on. It wont hurt to check. Does the CEL come on when you turn the key to position 1?

 

Hi , thank you for writing.
No there is no CEL.
the only code I have actually

Porsche P0230 Fuel Pump Open Primary Circuit

I know the driver side pump is gone, but this can’t be the reason for the bad emissions reading. iMO

 

Sorry to bother you with this problem. I am going to show you the reading from my OBD tool. Maybe somebody can read something out of this numbers.