P3404high severityPowertrain
Onboard Charger Ground Fault Detected
on 2010 Toyota Highlander 3.3L V6 Hybrid · AWD
What this code means
The onboard charger has detected a ground fault condition during charging, which triggers an immediate charge session stop for safety.
Symptoms
- Charging stops immediately
- Ground fault indicator on EVSE
- Charge session will not restart
- Intermittent charge interruptions
- Works at some locations but not others
Common causes
- Ground fault in vehicle wiring
- EVSE ground fault sensitivity
- Moisture in charge port
- Vehicle HV insulation degradation
- Home wiring ground issue
Diagnostic steps
- Test at multiple EVSE locations
- Inspect charge port for moisture
- Check vehicle HV isolation resistance
- Test home electrical outlet grounding
- Read OBC ground fault trip data
Repair notes
Dry charge port if moisture is present. Test HV system isolation. Have electrician verify home outlet grounding. Replace OBC if vehicle-side ground fault confirmed.
Other Powertrain codes on this vehicle
P0001
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P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1