What it means
The circuit signal for hybrid battery temperature sensor E is higher than expected. The code does not by itself identify the failed component.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Hybrid battery temperature sensor E measures temperature at its assigned point in the high-voltage battery pack and sends a signal to the control module. P0BC5 sets when that signal is higher than expected, which may result from a signal wire shorted to battery voltage, an open sensor, or a poor connector contact.
Common causes
Most likely first.
- Signal wire shorted to B+
- Open sensor
- Connector pins corroded - high contact resistance
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 sensor E temperature with the other pack temperature readings; a persistently implausible high reading points toward this circuit.
- With the vehicle powered down as directed by its service information, inspect sensor E's connector and harness for corrosion, loose pins, or damage that could expose the signal wire to battery voltage.
- Check that sensor E's connector is fully seated and its terminals are clean and secure, since poor contact can disrupt the signal.
- Use the manufacturer's wiring information to test the signal wire for a short to B+ and check circuit continuity.
- If the harness and connector pass, test sensor E against the manufacturer's specification for an open or failed element.
Common fixes
- Clean and properly seat corroded or loose sensor E connector terminals.
- Repair the signal wire shorted to B+ or the damaged section of harness.
- Replace sensor E if it is open or fails the specified test.
- Clear the code and verify sensor E's reading is plausible alongside the other pack sensors.
Can I keep driving?
Limit driving and avoid hard acceleration or charging until the fault is diagnosed, especially if power is reduced or a hybrid warning appears. A false temperature reading can cause protective limits or interfere with charging and electric range.
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.