Battery: Description and Operation

Battery Management System Description

This system consists of the battery sensor, the gauge control module, the driver's MICU, the passenger's MICU, the alternator, and the ECM/PCM.

The battery sensor measures the battery current, voltage, and temperature in all ignition switch positions. This data is used to control the alternator output, the idle speed, and the interior lights. These are the advantages of this system:

- Helps to prevent over-discharge of the battery.
- Helps to protect engine cranking amps.
- Helps to extend the battery life.
- Helps to improve fuel economy.
- Helps to alert the client of the battery condition.

Battery Management While the Ignition Switch is in LOCK (0), or the Vehicle Ignition is in the OFF mode, and With Electrical Devices ON

When the battery sensor detects the battery voltage decreasing, that information is sent to the gauge control module via the UART line. The gauge control module then operates a beeper, and displays the message Switch Off All Lights and Electrical Devices on the multi-information display (MID) to inform the client that electrical devices should be turned off. If electrical devices are not turned off and the battery voltage decreases more, the gauge control module sends an interior lights off signal to the driver's MICU and the passenger's MICU via the B-CAN line. Based on that signal, the units cut off the ground circuits of the interior lights and turns them off.






Battery Management While the Engine is Running

While the engine is idling, the battery sensor measures the battery current, voltage, and temperature values, and sends this data to the gauge control module via the UART line. The gauge control module sends the idle speed control signal and alternator control signal to the ECM/PCM via the F-CAN line. Then, based on those signals, the ECM/PCM determines the idle speed that is appropriate for the current state of charge of the battery, and also controls the alternator output. These functions help maintain the battery condition and improve the fuel economy.
If the battery sensor detects any problems, a warning message appears on the multi-information display (MID) to inform the client that the system needs attention.





NOTE:

- If there are any problems with the charging system or the battery, the charging system indicator comes on at the same time.
- The most common causes for "Battery Charge Low" messages are:
1: Short-trip driving.
2: Using the vehicles electrical devices, like the audio system, or aftermarket electrical devices for long periods of time with the engine OFF and the ignition switch is turned to ON (II), or the vehicle ignition is in the ON mode.
- If the "Battery Charge Low" warning appears after fully charging the battery, disconnect the gray 2-pin connector next to the Battery Sensor for 10 seconds, then reconnect the connector; and the warning is removed from the display.
- If you need to replace the battery, replace it with a new battery of the same group size.