DT Codes . com
DTC - Diagnostic Trouble Codes information

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.