Hi Everyone long time member but I haven't posted very often. I have a 2008 Cayenne Turbo with around 150k miles.

I had noticed that my throttle has been a little more sensitive than normal, but aside from that the truck ran fine so I checked the codes

I had gotten a few codes a few weeks ago for:
0121 throttle/pedal position position sensor
0524 Oil-pressure sensor
2181 Cooling system performance
0456 Evaporative emission system leak(very small leak)
1247 Basic boost pressure adaption

I cleared the codes and have been driving it since august 28.After clearing the codes the throttle was still a little more sensitive than normal, but aside from that the truck ran fine. I went to start it yesterday, and it cranked but didn't start. Then it started reved to 1800 and turned off. the code 1314 has showed up as well as 0700(transmission fault) and 1559(current power supply without engine operation)

Today I went out again to see if it would start, the first few times it kept saying step on break, which I was doing, and I am getting lights on in the dash for PSM failure, Chassis system faulty, Oil Pressure monitoring failure. The truck still either doesn't crank and says step on break, cranks and doesn't start or starts and dies.

Either I am having multiple system failures, or something links everything together. Any insight would be great I would rather not start buying random unnecessary parts.

All codes were scanned with an iCarsoft scan tool. I also have a durametric but I have not hooked that up yet.

 

Without starting the car try to open the power hatch 3 times in a row with the button. Does it open fully all 3 times or does the gate get stuck part of the way up.

Perosnlky, I think you have a weak battery. When you start getting a lot of different errors in unrelated systems, it's usually the battery.

For some reason, a Cayenne will still have enough juice to run the starter but not open the heavy lift gate repeatedly, so that's the reason for the first test.

 

Weak battery is a possibility, I will try that test when I get home. Thanks

 

ok the trunk will open repeatedly, i did it 6 times no problem. I also hooked up my durametric and a battery tester

battery is sitting at 11.73 volts and dropped to 7 when cranking

This is with a jumper pack connected






first time seeing this error

battery should be 1020CA 850CCA

 

That's a dead battery for sure.

 

Jump pack still wouldn't start it, and it still cranks over evem after dozens of trys. I have also had it start and die a few times

 

That big 8-cylinder engine needs a big jump pack, if You've tried with one of those small pocket size Li-Ion jumpers, it won't necessarily be enough. Can You try good old fashioned jumper cables from a running car or charge the battery with a battery charger until it's full, should be around 12.6-12.7V at rest. If the starter gets enough power and it still doesn't start, or tries to run but shuts down, take a look at the engine rpm reading while starting. What is it showing while starting? Should be a couple of hundred rpm, I don't know how much the normal starter speed is but at least ~200rpm is required for the ecu to start injecting fuel.

 

Is the tach needle jumping as the engine rotates with the starter. If not, the crankshaft position sensor or wiring to it has probably failed. It needs that signal to fire.

 

so I trickle charged the battery for 24 hours. Then I retested the battery and came up 12.5 volts and CCA was 879 and CA was 1032. both numbers above battery spec. I was able to start but it reved to 1500 on the tach, and then died. it started a few times, but dies within a second or 2. I am still getting dash warnings for oil pressure and psm failure. It will also say step on break, when I am. many times turning the key in the ignition does nothing. At this point I am not sure what direction to head.

 

I did have some water on the drivers side floor from ac overflow, is there anything else that could have leaked on? passenger side is bone dry. I have already done this in the past Cayenne DIY: Wiring problems due to moisture. All wires are soldered and shrink tubed

 

Durametric will no longer connect to my ECM, It reads all other codes but skips that, Is ecm failure common? Could it be as simple as swapping ecm?

 

Do you have the car running when trying to connect? Some modules I've noticed it won't connect to if the car isn't running.

 

Hi,

Did you manage to resolve this issue? I am having exactly the same issue with my 2007 4.8 porsche cayenne. Fitted new battery aswel and drove the car for a minute or 2. Wont start if warm and just goes off after 10-20 seconds of starting.

No issue at all until this (parked up for 2 months).

Code that appear are 1314 (crankshaft sensor) and 1826 (steering angle sensor).

Appreciate any advice or if this leads to a particular fault ?

 

Hello,
I am having the same issue as well Cayenne Base Model
PSM failure and car stops
did you find any solutions

 

There is another thread on this right now. Check the carpets by the front seats, is there water under there?

Mark