If the vehicle has been switched off for a lengthy period of time (longer than 68 minutes), the following Check Control message appears the next time the ignition or the engine is switched on: “Vehicle Battery! Increased Battery Discharge when engine off”. At the same time, the yellow lifting symbol in the instrument cluster lights up.
Retrofitted electrical after-market equipment (e.g., hands-free systems, navigation systems, GPS or entertainment systems) may have been incorrectly connected to Terminal 30, Terminal 30g-f or directly to the battery.
3 Bit Serial Data Interface (BSD) 4 Intelligent Battery Sensor (IBS) Index Explanation 1 B+ 2 B-3 Battery Voltage Measurement 4 BatteryTemp Measurement 5 Current Measurement 6 Microprocessor 7 BSD 8 DME/ECM. 9 E90 Voltage Supply & Bus Systems The IBS is able to withstand thermal loads up to 105°C, the chemical effects ofthe bat. A bit is transmitted by pulling low or shorting the bus with the ground momentarily. This is the reverse of many digital signals where the normal voltage is 0V and is raised high (Vmax which in this case is Vbatt or +12v) to send a bit. Serial communications on the bus are 9.6Kbps, 8 data bits, Even parity, and 1 stop bit. This is known as the Bit Serial Data Interface or BSD. BMW IBS sensor measures several battery parameters such as: Terminal Voltage; Charging current; Discharge current; Battery Temperature; SoC (State of Charge) SoH (State of Health; How to Troubleshoot BMW IBS Sensor. To find out if the IBS sensor on BMW is defective we scan the DME module.
Among other variables, the intelligent battery sensor (IBS) regularly monitors the battery’s discharge current while the vehicle is off. The measures values are transmitted to the DME/DDE through the bit-serial data interface (BSD).
If the measured off-load current exceeds a value of 80 mA once Terminal R is switched on after 68 minutes , the engine management system outputs the CC message “Vehicle Battery! Increased Battery Discharge” the next time Terminal 15 is switched on. This happens regardless of the battery state of charge.
Only install equipment or accessories which have been approved by BMW. Equipment or accessories must strictly only be connected to Terminal 15 or Terminal 30g, unless otherwise specified in the installation instructions of the BMW retrofit kit.
In the event of the situation described above, check the vehicle for non-approved installations and ask the customer whether components have been retrofitted.
-Service function
-Vehicle information
-Check control messages.
Bit Serial Data Interface Bmw Pdf
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