Hi

Had another older account but could not access so registered new one.

Hopefully someone can shed some light on a no start problem with my 2005 Cayenne TT.

I was on my way home and drove about 10 miles after the low gas light turned on. Normally I may risk driving 25 – 30 miles without worry after low gas light. This time the car died. I was able to coast to a safe spot and evaluation my situation. Tried to restart without success, the starter did not even turn. Illogically hoping it was just out of gas I called a friend. But after about 5 minutes I tried to start again and it started. I did notice it took slightly longer to start, maybe 1 second more than the usual instant start. Immediately racing to nearest gas station but car died again after about 1 mile. Waited another 5 minutes, started, drove another 1 miles or so. This time I waited for the 2 gallons of gas from friend. The additional gas didn’t seem to help but stalling 1 more time I eventually I made it to the gas station. Filled up and car ran fine again, perplexing but wasn’t going to complain. Drove home, let car idle for 30 minutes, all seemed good. Thought about faulty fuel pumps and stuffs.

Next morning car started right up drove 20 miles. Afternoon drove 4 miles, car died. This time the car could not start up again after 5 minutes, just cranks for about 2-3 seconds then total shut down, will not allow starter to turn. Waiting another 5 – 10 minutes car will allow starter to initiate for the 2-3 seconds but no start. Towed car home and thought the problem must be fuel pumps since gas tank was full.

Following days I changed both fuel pumps, fuel filter, and fuel pressure regulator hoping to avoid future problems since car already has 165,000 miles. No dice, exact same symptom, starter cranks no start then shut down, wait a few minutes will allow starter to crank again but will not start. Suspecting cause of no start unrelated or in additional to fuel pumps issue.

Checked fuel pumps with external 12v battery both work. Checked fuses and both relays, seems good but changed anyway. Checked again all fuel hoses not cracked or pinched, and connected correctly. The limit of my ability to locate the problem reached.

It didn’t feel like there was a catastrophic failure such as a blown engine. When car stalled it just lost power, no weird noise, nothing dramatic. I can hear the fuel pump priming for a second when driver door opens. Have not check fuel line pressure in engine compartment, should I check? Battery on trickle charger now voltage 13.1. I’m just a part changer clueless with electrical stuffs. No idea how to check control modules. Someone please help, or direct me to a good shop near Huntersville NC. Thank you, Lou.

Some more info that may be useful:

2005 Cayenne TT 165,000 miles
New battery March 2016
T hose back of intake January 2016 $2600 Ouch, stupid 50 dollar hose
Had to change T hose at a shop because I was 600 miles away from home
Oxygen sensors July 2014

- Changed these when car had rough start after gas fill up – February 2014
Venturi tube 94811007003
Vent Line Tank Ventilation 94811020201
Vent Line 94810721753

Change oil every 5000 – 8000 miles mobil 1
Spark plugs 120,000 miles
Coils 85,000 miles – still good no crack
Aluminum coolant hose 85,000 miles
Starter 85,000 miles

Here are fault codes from Durametric:

Bosch Digital Motor Electronics 7.1.1

P0685
ECM/PCM Power Relay Control Circuit - No signal/communication, test conditions are not-completed, fault is not currently active and is not causing a DTC light

P1549
Vehicle electrical system voltage via main relay - No signal/communication, test conditions are not-completed, fault is not currently active and is not causing a DTC light

P1550
- Implausible signal, test conditions are not-completed, fault is currently active and is not causing a DTC light

P0198
- Upper limit value exceeded, test conditions are not-completed, fault is currently active and is not causing a DTC light

Tiptronic Transmission

1314
DME control module - No signal/communication, test conditions are not-completed, fault is currently active and causing a DTC light

Instrument Cluster for Cayenne

771
Fuel level sensor 1 - Open circuit/short circuit to B+, test conditions are not-completed, fault is not currently active and is not causing a DTC light

438
Fuel level sensor 2 - Open circuit/short circuit to B+, test conditions are not-completed, fault is not currently active and is not causing a DTC light

562
Oil level sensor - Implausible signal, test conditions are not-completed, fault is not currently active and is not causing a DTC light

1314
DME control module - No signal/communication, test conditions are not-completed, fault is not currently active and is not causing a DTC light

Gateway

1314
DME control module

 

Did you check the High pressure pump?

 

I didn't know there is a high pressure fuel pump. Is there one for the 955 2005?

I've read about 957 year 2008 and up having a high pressure pump.

Where is the pump?

Thanks

 

I'm 98% sure if it's a Turbo it has a High pressure pump. The all the 957's had the High pressure pumps. I think for the 955 only the Turbo and Turbo S had the high pressure fuel pumps.

I'm assuming the high pressure would be located in the same spot as the 957?

 

Interesting, I will look into it. Hopefully there is one and is the problem, hate to tow it to dealer and find out is something I can fix myself. Thanks

 

The 4.5 litre engine does not have a High pressure fuel pump.

The 4.8 litre DFI engines have a high pressure pump.

 

I would have a look at the crankshaft position sensor / circuit.

When the sensor starts to fail, the car will exhibit similar engine problems like yours and there is no direct correlated fault code for the sensor / circuit fault.

Here is a link with more info.

http://www.pelicanparts.com/techarti...eplacement.htm

 

Just take it to Porsche and have them fix. It's so much easier then guessing and all.

 

I had both my Fuel pumps done at Porsche... Dealer service is the way to go

 

I will take a look at the crankshaft position sensor / circuit.

But I have a feeling eventually will need porsche dealer service like Porscheman33 said.

Does anyone know of any other good porsche mechanic at or near Charlotte / Huntersville area beside Hendrick porsche dealer. Someone suggested Exclusive Motorwerks at Denver, but they seem to be specialized on 911. When I had my cayenne repaired in NYC at a place specialized on 911, they didn't really know their way around cayenne well.

Thanks for the help all.

 

The Crankshaft position sensor could also be an issue as the other guy said, I'd post in the regional section to see if anyone trust any shops. I find that most shops don't have experience working on the Cayennes. 911's yes but thats about it. Some things are just better by going to the dealership. It goes in once and gets resolved rather then going in two or three times and not even being able to find the issue, and you end up going to Porsche in the end anyway.

 

FYI Ben through all posts on the same problem that I see here and don’t see any talk about checking fuel pump relay .
I changed this $14.00 part. And car started!
( relay panel LH front under hood relay had #167 on it. Part # 191 906 383C.
hope this help.