Charging System
The PCM-controlled, or Smart Charge charging system determines the optimal voltage setpoint for the charging system and communicates this information to the voltage regulator. The Smart Charge charging system is designed to set 1 of 7 Diagnostic Trouble Codes (DTCs) any time a charging system fault is present. All of the Diagnostic Trouble Codes (DTCs) can set continuous faults, but not all Diagnostic Trouble Codes (DTCs) set as on-demand faults.
| Diagnostic Trouble Code (DTC) | Key ON Engine OFF (KOEO) | Key ON Engine Running (KOER) | Continuous |
|---|---|---|---|
| P0562 | X | X | X |
| P0563 | X Requires vehicle speed above 8 mph. | X | |
| P065B | X | X | |
| P065C | X | X | |
| P0A3B | X | X | |
| P1397 | X | X | |
| U012D | X | X | X |
| U042E | X | X | |
| Parameter Identification (PID) | Description | Normal Display |
|---|---|---|
| GEN_FAULT | Generator Fault Status | No Fault |
| GEN_LOSTCOMM | Lost Communication with Starter/Generator Control Module | No Fault |
| GENFIL | Generator Fault Indicator Lamp | OFF |
| GENREG_ELEC_F | Generator Regulator Reporting Electrical Fault | No Fault |
| GENREG_INVCMD | Generator Regulator Receiving Invalid Commands | No Fault |
| GENREG_MECH_F | Generator Regulator Reporting Mechanical Fault | No Fault |
| GENREG_NOCMD | Generator Regulator Indicating Missing Commands | No Fault |
| GENREG_OVRTMP | Generator Regulator Indicating Over Temperature | No Fault |
| GENVDSD | Generator Voltage Desired | Voltage varies by vehicle needs - May be controlled by an output state control |
| RPM | Engine Revolutions Per Minute | Engine Revolutions Per Minute (RPM) - May be controlled by an output state control |
| VPWR | Module Supply Voltage | Within 0.5 volt of battery voltage |
The PCM simultaneously controls and monitors the output of the generator. When the current consumption is high or the battery is discharged, the PCM raises engine speed as needed to increase generator output. The generator charges the battery and at the same time supplies power for all of the electrical loads that are required. The battery is more effectively charged with a higher voltage when the battery is cold and a lower voltage when the battery is warm.
The PCM turns off the generator during cranking to reduce the generator load and improve cranking speed. Once the engine starts, the PCM slowly increases generator output to the desired voltage.
The PCM reports any charging system faults and sends a message through the HS-CAN to the BCM. The BCM then sends a message over the MS-CAN to the IPC, which controls the charging system warning indicator. The status of the PCM charging system warning indicator message can be confirmed by viewing the PCM Generator Fault Indicator Lamp (GENFIL) PID. Any charging system fault detected by the PCM results in 1 or more Diagnostic Trouble Codes (DTCs) being set and the GENFIL PID having a status of ON. The IPC turns the charging system warning indicator ON and the message center may display a corresponding message to notify the driver of the condition.
Under certain circumstances, the charging system may have a concern but still keep the battery charged while the vehicle is running. The LIN is normally used to initiate charging, but with a fault on this circuit, the generator can self-excite, or begin charging on its own. The engine may need to operate at more than 2, 000 RPM momentarily for this to occur. The charging system warning indicator illuminates, the corresponding message is displayed and the generator operates in a default mode (approximately 13.5 volts).