What it means
The control module detects a correlation fault between hybrid/EV battery pack current sensors A and B.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Battery pack current sensors A and B provide current readings that the control module can compare for consistency. P0B13 sets when their readings do not correlate as expected, pointing to a possible fault in either sensor, its circuit, or a shared electrical connection.
Common causes
Most likely first.
- One current sensor or its circuit is faulty
- Wiring or connector fault
- Electrical connection or reference fault
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 readings from current sensors A and B during the same operating conditions to identify which reading diverges.
- With the vehicle powered down as specified by the manufacturer, inspect both sensors' accessible connectors and wiring for damage, corrosion, loose terminals, or poor seating.
- Check for other current-sensor, reference, or ground codes that may identify a shared electrical fault.
- Using the wiring diagram, test the power, ground, reference, and signal circuits for sensors A and B against the manufacturer's specification.
- If the circuits check out, compare each sensor's output with the manufacturer's specification under matching conditions to isolate the faulty sensor.
Common fixes
- Reseat and secure the connector for the sensor with a poor connection.
- Repair damaged wiring or faulty shared reference or ground connections.
- Repair the signal circuit identified as out of specification.
- Replace sensor A or B only after tests identify which sensor is causing the mismatch.
Can I keep driving?
Limit driving if power is reduced or charging is affected, and avoid depending on the vehicle's electric range. Stop if propulsion becomes unreliable; conflicting current readings can make the control module 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.