Principles of Operation

PRINCIPLES OF OPERATION

This vehicle is equipped with a powertrain control module (PCM)-controlled charging system; the PCM determines the optimal voltage setpoint for the charging system and communicates this information to the voltage regulator. The PCM-controlled charging system is unique in that it has two unidirectional communication lines between the PCM and the generator/regulator. Both of these
communication lines are pulse-width modulated. The generator communication (GEN COM) line communicates the desired setpoint from the PCM to the voltage regulator and the generator monitor (GEN MON) line communicates the generator load and error conditions to the PCM. The third pin on the voltage regulator, the A circuit pin, is a dedicated battery voltage sense line.

Circuit Description

Circuit 1182 (OG/YE)
This is the A terminal battery voltage sense circuit and is used to sense battery voltage.

Circuit 1181 (GY/YE) (GEN MON)
This is the generator monitor (GEN MON) circuit. The PCM monitors this circuit to determine the generator load and error conditions to the PCM.

Circuit 3990 (LB/RD) (GEN COM)
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.