System Description

WARNING: This page is about a different car, the 2005 Infiniti FX45 and 2005 Infiniti FX35. However, it is still accessible from the selected car via links, so may be relevant.

Power is supplied at all times

Through 40A fusible link (letter F, located in the fuse and fusible link block)
to ignition switch terminal 1,
Through 15A fuse (No. 78, located in the IPDM E/R)
to CPU of IPDM E/R,
Through 10A fuse (No. 71, located in the IPDM E/R)
to CPU of IPDM E/R.
When the selector lever in the P or N position, power is supplied
from TCM, and through A/T assembly terminal 9
to IPDM E/R terminal 53.
Ground is supplied
to IPDM E/R terminals 38, 50 and 60
from grounds E21, E50 and E51.
With the ignition switch in the START position, and provided that the IPDM E/R receives a starter relay ON signal from the CAN lines, the IPDM E/R is energized and power is supplied
from ignition switch terminal 5
to IPDM E/R terminal 4 and
Through IPDM E/R terminal 3
to starter motor terminal 1.
The starter motor plunger closes and provides a closed circuit between the battery and starter motor. The starter motor is grounded to the engine block. With power and ground supplied, cranking occurs and the engine starts.