What it means
The ECM detects a circuit low fault on the battery charger b coupler lock position sensor circuit. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
How it works
The battery charger B coupler lock position sensor circuit carries the signal used to determine whether the charging coupler is locked. This code sets when the signal is lower than the control module's expected range, commonly because the signal is grounded, the sensor is internally shorted, or connector contact is poor.
Common causes
Most likely first.
- Signal wire shorted to ground
- Internal sensor short
- Connector pins corroded - high contact resistance
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
How to diagnose it
- Review freeze-frame data and charging-related codes to confirm the low signal occurred on charger B's coupler lock position circuit.
- Inspect the sensor connector and accessible wiring for corrosion, damage, or a signal wire rubbed through against ground.
- Check that the connector is fully seated and that its terminals are not visibly corroded or pushed back.
- Use scan-tool live data to confirm the position reading stays low as the coupler lock is moved normally.
- Test the signal circuit for a short to ground and check sensor operation to the manufacturer's specification.
Common fixes
- Reconnect a loose sensor connector.
- Repair the signal wire where it is shorted to ground.
- Repair corroded or damaged sensor connector terminals.
- Replace the sensor if testing confirms an internal short.
Can I keep driving?
The charger may not accept or maintain a connection if it cannot read the coupler lock position. Do not bypass the lock or force the coupler; stop charging if the lock status is uncertain.
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.