DTC Descriptor
WARNING: This page is about a different car, the 2007 Suzuki XL7. However, it is still accessible from the selected car via links, so may be relevant.
DTC P0601 Control Module Read Only Memory (ROM)
DTC P0602 Control Module Not Programmed
DTC P0603 Control Module (TCM) Long Term Memory Reset
DTC P0604 Control Module Random Access Memory (RAM)