Fault memory
WARNING: This page is about a different car, the 2006 Porsche Cayenne, 2005 Porsche Cayenne, 2004 Porsche Cayenne, and 2003 Porsche Cayenne. However, it is still accessible from the selected car via links, so may be relevant.
Faults that occur during operation are stored in a non-volatile memory (e.g. EEPROM). The faults remain in the memory even if terminal 15 and terminal 30 are not live. The fault memory is designed in such a way that the occurring faults, data source, fault type and fault deletion counter can be saved. The transfer box control module sends messages and checks the CAN drive cyclically for messages from other control modules. If no messages are received for a certain time period, a fault is stored in the fault memory.