Circuit 920 (BN/WH)
WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
This is the generator communication (GEN COM) circuit. The PCM determines the optimal voltage setpoint for the charging system and communicates this information to the voltage regulator through the GEN COM circuit.