2. Detect Malfunctioning Part

WARNING: This page is about a different car, the 2004 Infiniti G35. However, it is still accessible from the selected car via links, so may be relevant.

Check the following.

40A fusible links
Harness for open or short between IPDM E/R and battery
1. Repair open circuit or short to ground or short to power in harness or connectors.