What it means
The control module detects a low signal in the hybrid/EV battery pack voltage sense B circuit.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The battery pack voltage sense B circuit sends a battery voltage measurement to the control module. P0B16 sets when the signal falls below the expected range, which can result from a short to ground, a sensing-circuit fault, or a poor connection.
Common causes
Most likely first.
- Signal wire shorted to ground
- Sensing circuit fault
- Poor electrical connection
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
How to diagnose it
- Record freeze-frame data and compare live voltage sense B data with other battery voltage readings to confirm that B is abnormally low.
- With the vehicle powered down as specified by the manufacturer, inspect sense B's wiring and connector for damage, corrosion, loose terminals, or a wire shorted to ground.
- Check for related low-voltage or battery sensing codes that may indicate a shared reference or ground issue.
- Using the wiring diagram, test the sense B signal wire for a short to ground and check its reference and ground connections.
- Compare the circuit and sensing component readings with the manufacturer's specification to locate the cause of the low signal.
Common fixes
- Reseat the sense B connector and repair loose or corroded terminals.
- Repair a signal wire shorted to ground or other damaged wiring.
- Restore a faulty reference or ground connection to specification.
- Replace the sensing component if the signal remains low after circuit faults are ruled out.
Can I keep driving?
Avoid relying on electric propulsion or charging while the vehicle has reduced power or a battery system warning. Stop if the warning indicates a battery hazard or power becomes unpredictable, since the system may restrict battery operation.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.