Principles of Operation

CHARGING SYSTEM

The generator on this vehicle has built-in voltage regulator set point. The generator decides optimal charging system voltage based on temperature. The generator has a communication line (GEN MON) to the PCM, which indicates the generator operating duty cycle. This is a pulse width modulated signal. The communication line (GEN MON) is used for fault indication as well. The generator has an I-terminal used for initially turning on the generator. The generator has a battery sense terminal (A-terminal).

B+ Output Circuit 30-BA6 (RD)
Generator output voltage is supplied through the battery positive (B+) output terminal on the rear of the generator to the battery and the electrical system.

Circuit 30-BA25 (RD)
This is the battery voltage sense or A circuit and is used to sense battery voltage.

Circuit 10-BA25 (GY/RD)
This is the generator I-circuit. This terminal is used to turn the generator on initially. Once the generator is turned on, the generator will only turn off when engine is shut down.

NOTE: If the I-circuit 10-BA25 (GY/RD) is open or shorted to ground, the generator will not function. If the engine speed exceeds 3000 rpm, the generator will self-excite, and begin to function normally (the battery light will turn off and the generator will operate normally) until the engine is turned off.

This is a limp-home mode for customer safety.

Circuit 8-BA25 (WH/RD)
The generator monitor (GEN MON) communicates the generator load and error conditions to the PCM. The PCM will send a signal to the instrument cluster using the Standard Corporate Protocol (SCP) bus to turn on the charging system warning indicator if there is an error condition.