Principles of Operation
PRINCIPLES OF OPERATIONThe generator on this vehicle has a 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 powertrain control module (PCM), which indicates the generator operating duty cycle. This is a pulse width modulated (PWM) 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 also 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)
The generator I-circuit terminal is used to turn the generator on initially. Once the generator is turned on, the generator only turns off when the engine is shut down. If the I-circuit 10-BA25 (GY/RD) is open or shorted to ground, the generator does not function. If the engine speed exceeds 3,000 rpm, the generator self-excites, and begins to function normally (the battery light turns off and the generator operates 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 sends 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.