Onboard Charger (OBC) Internal Fault
2012-2017 Buick Regal 2.4L I4 Hybrid
Description
The onboard charger has detected an internal fault that prevents AC charging. The OBC converts AC power from the charging inlet to DC for the battery.
Symptoms
- Vehicle will not charge from AC source
- Charging indicator shows fault
- Reduced charging speed
- Charge session terminates unexpectedly
- Error message on dashboard
- Charging light flashing red
Common Causes
- OBC power electronics failure
- Internal relay failure
- PFC circuit malfunction
- Output rectifier failure
- Control board fault
Diagnostic Steps
- Attempt charge session and read OBC fault codes
- Monitor OBC input and output voltage during charge
- Check OBC coolant temperature
- Inspect OBC connectors
- Test charging with different EVSE equipment
Repair Notes
Replace onboard charger assembly. Verify charging operation with Level 1 and Level 2 EVSE after replacement.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P3400 on Other Vehicles
Common Questions
What does code P3400 mean on a 2012-2017 Buick Regal?
P3400 stands for "Onboard Charger (OBC) Internal Fault". The onboard charger has detected an internal fault that prevents AC charging. The OBC converts AC power from the charging inlet to DC for the battery.
What are the symptoms of P3400 on a Buick Regal?
Common symptoms of P3400 include: Vehicle will not charge from AC source, Charging indicator shows fault, Reduced charging speed, Charge session terminates unexpectedly, Error message on dashboard, Charging light flashing red.
What causes P3400 on a 2012-2017 Buick Regal?
Common causes of P3400 include: OBC power electronics failure, Internal relay failure, PFC circuit malfunction, Output rectifier failure, Control board fault.