Battery Monitoring System Control Module
The Battery Monitoring System (BMS) control module is located on the startup battery jump start ground terminal and is clamped to the terminal with a bolt and nut. The startup battery jump start ground cable is connected to the BMS control module and is attached to a ground stud on the vehicle body.
The BMS control module is connected into the vehicle wiring harness via a multiplug. The BMS control module receives a 12V power supply direct from the startup battery positive terminal. A Local Interconnect Network (LIN) bus connection provides communication between the BMS control module, the Body Control Module/Gateway Module (BCM/GWM) and the Quiescent Current Control Module (QCCM). The LIN connection is used for control and monitoring of the startup battery current drain and state of charge.
The BMS control module measures the startup battery current and voltage, which transmits it to the BCM/GWM over the LIN bus connection. The BCM/GWM also receives generator output information on a LIN bus connection. Based on the information received from the BMS control module, the BCM/GWM will control the output from the generator and request the switching off of electrical loads if necessary.
The BMS control module is able to generate Diagnostic Trouble Codes (DTCs) to help diagnose startup battery or generator power supply issues. These DTCs can be read using the Jaguar Land Rover (JLR) approved diagnostic equipment. The JLR approved diagnostic equipment can also be used to implement a startup battery and generator self-test routine.
If a fault is detected, the BCM/GWM and the Powertrain Control Module (PCM) will override the BMS control module.
The BMS control module DTCs can be used to help diagnose startup battery or generator power supply faults. The DTCs are stored in BCM/GWM. The JLR approved diagnostic equipment has a process for an automated power supply diagnostic procedure. The procedure provides a menu driven process to locate a fault in a logical sequence. The procedure uses the capability of the BMS control module and generator LIN bus controlled functions to provide current flow information. It additionally detects if the BMS control module or generator are functioning correctly.