VOLVO
BECM-P0B4700 - Hybrid/EV Battery Voltage Sense "C" Circuit Low. General Failure Information. No sub type information
System
Battery Energy Control Module (BECM)
Volvo models this fault code applies to
Applies to the following models:
1 modelV60 (2011–)
Show models by year and engine (2)
What does this fault code mean?
The BECM monitors the voltage across the battery cells in the high voltage battery. The code is set when the voltage in cell monitoring C is too low. The cause may be incorrect charging, for example from an external cable, with the combustion engine running or through brake energy recovery, or a damaged battery.
Possible causes
- Incorrect charging from the external charging cable, where the fault may lie in the on-board charger (OBC)
- Incorrect charging with the combustion engine running, where the fault may lie in the engine control module (ECM) or the high voltage generator (IGM)
- Incorrect charging through brake energy recovery, where the fault may lie in the electric rear axle (IEM)
- The high voltage battery is damaged
What you can do
- 1Read and note the fault code, clear it and road test to check whether it returns
- 2Has the car recently been charged from an external cable or driven with heavy brake energy recovery?
- 3Have a workshop read the fault codes in the charger, the engine control module, the high voltage generator and the electric rear axle
- 4Have a workshop with diagnostic equipment check cell monitoring C in the high voltage battery
- 5The high voltage system should only be handled by qualified personnel, so have a workshop carry out all work on the battery and other high voltage parts
Symptoms you may notice4
- Red warning symbol and message in the display
- Charging of the high voltage battery stops or works poorly
- Drive modes PURE, SAVE and AWD disengage automatically or cannot be selected
- The combustion engine runs more often than normal in HYBRID mode
What the fault can affect2
- The high voltage battery cannot be charged
- Electric propulsion is not possible
General guidance for car owners. Diagnosis on the car can point to a different cause.