08 V6 fuel pump relay
04-21-2021, 08:32 PM
#1
Nordschleife Master
Thread Starter
08 V6 fuel pump relay
Hello All,
I am helping a friend with his 08 V6 Cayenne with DFI.
The vehicle would randomly die and waiting 30 min or so it would fire right back up.
The code it throws is always low fuel pressure.
We replaced the in-tank pumps (the vehicle has 222k and they had never been done). We then replaced the pressure sensor and high-pressure pump.
After replacing those parts it ran great for a little longer then would start and run for a minute or 2 then stall out.
I was able to track it down to the fuel pump relay losing its activation power. I can remove the relay and jumper and then it runs for as long as is needed.
Can anyone provide details on how the ECU determines what is needed to keep that relay activated? Or are we looking at a defective ECU?
TIA.
I am helping a friend with his 08 V6 Cayenne with DFI.
The vehicle would randomly die and waiting 30 min or so it would fire right back up.
The code it throws is always low fuel pressure.
We replaced the in-tank pumps (the vehicle has 222k and they had never been done). We then replaced the pressure sensor and high-pressure pump.
After replacing those parts it ran great for a little longer then would start and run for a minute or 2 then stall out.
I was able to track it down to the fuel pump relay losing its activation power. I can remove the relay and jumper and then it runs for as long as is needed.
Can anyone provide details on how the ECU determines what is needed to keep that relay activated? Or are we looking at a defective ECU?
TIA.
