P0B6E

What it means

P0B6E is the generic code for a range or performance fault in the 'K' voltage sense circuit of the hybrid or EV traction battery. The battery control unit compares the reading from this sense circuit with the other sense circuits and with the total pack voltage. It set the code because the reading was implausible, drifting or out of step with what it expected. Which cells or modules 'K' covers depends on the make, model and battery design.

Symptoms

• Hybrid or EV system warning light on, often with the main warning light
• Reduced power or the car going into a limited performance mode
• Reduced or no electric assist or regeneration
• Erratic or jumping state of charge reading
• Engine running more than normal on a hybrid
• In some cases the car will not go to Ready or will not charge

Possible causes

• Poor connection, corrosion or a loose terminal in the voltage sense wiring or connector for circuit Klikely
• Damaged, chafed or open-circuit sense wire between the battery cells or modules and the monitoring unitlikely
• Fault in the battery monitoring unit or cell voltage sensing electronicspossible
• Genuine cell or module imbalance or a weak cell in the group measured by circuit Kpossible
• Loose or corroded busbar or module connection inside the battery packpossible
• Water ingress or contamination in the battery pack or its connectorsrare
• Outdated battery control software where the manufacturer has issued a fix for this faultrare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, and note any other battery voltage sense, cell balance or insulation codes.
2. Check for manufacturer bulletins and known issues for this model and battery type, as the layout of the K circuit varies.
3. With the high voltage system made safe by a trained technician following the manufacturer's procedure, visually inspect the sense wiring, connectors and plug for damage, corrosion, water or heat marks.
4. Using live data, compare individual cell or module voltages, looking for one group that reads wrongly, jumps about or differs from the rest.
5. Check the pack total voltage against the sum of the group readings to see whether the fault is in the measurement or in the battery.
6. Test the sense circuit wiring for continuity, resistance and shorts, following the model wiring diagram.
7. Wiggle-test the harness and connector while watching live data for dropouts.
8. Check battery cooling and ventilation paths for blockage, as heat can affect cell condition and readings.

How to fix

• Clean, repair or replace the damaged connector, terminal or sense wiring.
• Tighten or repair loose busbar or module connections, following the manufacturer's procedure.
• Replace or repair the faulty battery monitoring unit or sensing module if the wiring and cells are sound.
• Rebalance or replace the weak cell or module, or the pack, where testing confirms a genuine battery fault.
• Dry, clean and seal the pack and connectors where water ingress is found, and fix the source of the leak.
• Update the battery control software only if the manufacturer lists it as the fix for this fault.

Can I keep driving?

Nearby codes

• P0B6DGenericHybrid/EV Battery Voltage Sense K Circuit
• P0B6FGenericHybrid/EV Battery Voltage Sense K Circuit Low