Are you driving a Carrera? Or, a Boxster with a Carrera instrument cluster? If either is the case, plus the On Board Computer (OBC) is the origin of your "failure indicator" message and the oil pressure "idiot light" is
not illuminated, I would suggest that the indicator part of the oil pressure transmitter has failed (the idiot light part is still functioning). The Carrera Owner's Manual says "Oil pressure indicator is faulty. Have the fault remedied at an authorized Porsche dealer.
If the idiot light
is illuminated, don't run the engine....especially if the oil level is "normal". It could be a failed oil pressure transmitter - both the indicator part and the idiot light part. But, it could also indicate a true oil pressure problem.
The Carrera oil pressure transmitter has two connectors, one for the oil pressure indicator gauge and one for the idiot light. The Boxster oil pressure transmitter has only one connector - for the idiot light.
The oil pressure transmitter for a Carrera is: 996.606.203.02 - MSRP US$66.60 / CAN$80.02.
The transmitter is located on the top of the cam cover on the front passenger side (US) of the engine.Some people have managed to change the transmitter by reaching it from inside the engine compartment. Others have accessed the transmitter from the right rear wheel well by removing the wheel and liner panel.
Bill