P0400 - Exhaust Gas Recirculation Flow Malfunction
Possible causes
- Exhaust Gas Recirculation (EGR) solenoid valve harness is open or shorted
- Exhaust Gas Recirculation (EGR) solenoid valve circuit poor electrical connection
- Exhaust Gas Recirculation (EGR) volume control valve stuck closed
- Faulty Exhaust Gas Recirculation (EGR) volume control solenoid valve
- Dead (Weak) battery
- Faulty EGR temperature sensor and circuit
- Faulty EGR Valve