What it means
The control module detects a high 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. P0B17 sets when the signal rises above the expected range, which can result from a short to voltage, an open sensing circuit, or a poor connection.
Common causes
Most likely first.
- Signal wire shorted to voltage
- Open sensing circuit
- 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 readings with other battery voltage data to confirm that B is abnormally high.
- With the vehicle powered down as specified by the manufacturer, inspect sense B wiring and connectors for damage, corrosion, loose terminals, or contact with a voltage source.
- Check for related circuit or reference codes that could point to an open or shared electrical fault.
- Using the wiring diagram, test the sense B signal wire for a short to voltage and check circuit continuity for an open.
- Compare the circuit readings with the manufacturer's specification to determine whether the fault lies in the wiring, connection, or sensing component.
Common fixes
- Reseat the sense B connector and repair loose or corroded terminals.
- Repair a signal wire shorted to voltage or other damaged wiring.
- Restore continuity in an open voltage sense B circuit.
- Replace the sensing component if its output remains high after wiring and connections are verified.
Can I keep driving?
Limit driving if the vehicle has reduced power, charging trouble, or an EV system warning, and avoid trips that rely on electric range. Stop if power becomes unpredictable; a falsely high battery voltage reading can cause the system to restrict battery use.
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.