What it means
The battery charger input circuit reports a circuit intermittent/erratic condition. AC mains/EVSE input may be impaired.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The onboard charger monitors its AC input from the EVSE or mains supply while a charging session is active. P0D84 sets when that input signal fluctuates or drops in and out, which can reflect a poorly seated connector, unstable ground reference, or vibration-sensitive contact.
Common causes
Most likely first.
- Connector not seated
- Noisy ground reference
- Connector with intermittent contact under vibration
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
How to diagnose it
- Review the charge-session history or freeze-frame data to see whether the fault coincides with charging interruptions or a change in input readings.
- Check whether the issue occurs with one EVSE or outlet, then try a compatible known-good charging source if available.
- With charging stopped, inspect that the vehicle inlet and EVSE plug are fully seated and look for damaged, dirty, or discolored contacts.
- Have a qualified technician inspect input wiring and ground connections, including checks for intermittent contact while safely testing the circuit.
- If connections and supply remain stable, test onboard charger input monitoring using the manufacturer's diagnostic procedure.
Common fixes
- Reseat the vehicle connector and EVSE plug firmly.
- Clean or repair a connection only as permitted by the vehicle and EVSE instructions.
- Repair a loose ground or intermittent input-circuit connection.
- Replace a faulty EVSE or repair the onboard charger if testing isolates the fault there.
Can I keep driving?
Charging may fail to start, interrupt, or proceed more slowly than expected. Check the displayed charge status and do not leave the vehicle relying on an interrupted session for needed 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.