5. Detect Malfunctioning Part

WARNING: This page is about a different car, the 2004 Infiniti M45. However, it is still accessible from the selected car via links, so may be relevant.

Check the following.

Harness connectors M401, M61
Harness connectors M135, F105
Joint connector-7
Harness for open or short between ECM and stop lamp switch
: Repair open circuit or short to ground or short to power in harness or connectors.