P0400
Powertrain Codes
P0400 - Exhaust Gas Recirculation Flow Malfunction
Symptoms
- Engine Light ON (or Service Engine Soon Warning Light) - Engine hesitation
Possible Causes
- Harness or connectors (EGR volume control valve circuit is open or shorted.) - EGR volume control valve stuck closed - EGR volume control solenoid valve - Dead (Weak) battery - EGR temperature sensor and circuit - EGR Valve
When Detected
- EGR flow control is not responding
Description
Early Models : The EGR valve control the amount of exhaust gas routed to the intake manifold. Vacuum is applied to the EGR valve in response to the throttle opening. The vacuum control the movement of the taper valve connected to the vacuum diaphragm in the EGR valve.