On Board Diagnosis Logic

WARNING: This page is about a different car, the 2012 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

This is not an OBD-II self-diagnostic item.
Diagnostic trouble code "P1731" with CONSULT or 13th judgment flicker without CONSULT is detected under the following conditions.

When TCM does not receive the proper voltage signal from the sensor.
When TCM monitors each ATF pressure switch and solenoid monitor value, and detects as irregular when engine brake of 1st gear acts other than at "1" position.