Battery Monitoring Sensor
The intelligent sensor clamped to the twelve-volt battery's negative terminal, measuring current in and out, terminal voltage and temperature so the module can calculate state of charge and state of health. It is what makes regulated charging possible — the alternator is commanded rather than left to charge blindly — and it is a different part from the battery temperature sensor, which measures only temperature.
State of charge is an accounting figure, not a voltage reading, which is the thing to understand about its faults. The module integrates charge in and out over time against the battery's known characteristics. So the calculation depends on the module being told what battery is fitted — which is why a replacement usually has to be registered or coded, and why one fitted without that step produces charging and stop-start faults with entirely sound hardware.
It fails quietly and expensively. A sensor reporting a healthier battery than exists lets the alternator undercharge, which sulphates the battery over months; one reporting worse overcaches it. A car on its third battery in a few years is worth checking here rather than buying a fourth. Its clamp connection also corrodes, and a poor joint at the terminal reads as a sensor fault.
Also known as: ibs, intelligent battery sensor, battery current sensor 12v, battery state of charge sensor, battery management sensor
Referenced by 10 codes
Codes involving this component (10)
- P00FD Battery B State of Charge Performance Moderate
- P058C Battery Monitor Module Temperature Monitoring Performance Moderate
- U04B1 Invalid Data Received From Battery Monitor Module Moderate
- P057F Battery A State of Charge Performance
- P058A Battery Monitor Module Performance
- P058B Battery Monitor Module Current Monitoring Performance
- P058D Battery Monitor Module Voltage Monitoring Performance
- P058E Battery Monitor Module Temperature Too High
- P058F Battery Monitor Module Temperature Too Low
- U01B0 Lost Communication With Battery Monitor Module
Other components in Electrical and Charging
- Data Bus 563
- Battery 218
- Gateway Module 158
- Stability Control Module 122
- Battery Temperature Sensor 115
- Infotainment Head Unit 49
- Alternator 45
- Brake Booster Pressure Sensor 39
- A/C Refrigerant Pressure Sensor 33
- Brake Light Switch 32
- Cruise Control Switch 31
- Ignition Switch 31
- Cooling Fan Relay 28
- Starter Relay 25
- A/C Compressor 25
- Clutch Switch 24
- ECM Power Relay 21
- Roof Antenna Module 19
- Immobiliser 15
- Lighting Driver Control Module 15
- Starter Motor 14
- Transmission Control Module Power Relay 14
- Fuel Pump Relay 13
- Secondary Air Injection Relay 13
- Driver Information Centre 10
- A/C Evaporator Temperature Sensor 8
- Telematics Control Module 8
- Navigation Control Module 6
- Headlamp Levelling Actuator 6
- Hydraulic Pump Relay 5
- Head-Up Display 2
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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