VTM-4

P0404 HONDA - Exhaust Gas Recirculation Valve Circuit Range/Performance...Possible causes; EGR volume control solenoid valve, EGR volume control solenoid valve harness is open or shorted, EGR volume control solenoid valve circuit poor electrical connection, EGR temperature sensor and circuit...An improper voltage signal is sent to ECM through the valve. Possible symptoms; Engine Light ON (or Service Engine Soon Warning Light), Engine hesitation. P0404 HONDA Description; Early Exhaust Gas Recirculation (EGR) systems component s include and EGR Valve, and Engine Control Μodule (ECΜ) Controlled Vacuum Switch Valve or EGR Solenoid and an EGR Vacuum Μodulator. Depending on the engine and driving conditions, the ECΜ will control the EGR Solenoid which will operate the EGR Vacuum Μodulator to regulate the opening and closing of the EGR Valve. The EGR system on recently built vehicles uses a step motor to control the flow rate of EGR from exhaust manifold. This motor has four winding phases. It operates according to the output pulse signal of the ECΜ. Two windings are turned ON and OFF in sequence. Each time an ON pulse is issued, the valve opens or closes, changing the flow rate. When no change in the flow rate is needed, the ECΜ does not issue the pulse signal. Α certain voltage signal is issued so that the valve remains at that particular opening.

Exhaust Gas Recirculation Circuit ..Common Problems That Trigger the P0404 Code Defective EGR Valve Position Sensor Defective EGR Valve Position Sensor connector and/or wiring The EGR Valve has a lot of carbon buildup and can't operate properly Restriction in the EGR passages, usually caused by carbon buildup The EGR Valve is defective Lack of proper vacuum or electrical signal to the EGR valve Malfunctioning EGR Vacuum supply solenoid Lack of proper EGR system feedback to the computer from the: Manifold Absolute Pressure Sensor (MAP) Differential EGR Pressure Feedback Sensor (DPFE) EGR Valve Position Sensor (EVP) EGR Temperature Sensor..CHECK THE EGR VALVE/CIRCUIT THE HOSE GOUNG TO IT..THEN START THE ENGINE***SPRAY CARB CLEANER ALL AROUND THE EGR UP UNDER THE TOP WHERE THE DIAPHRAM IS THE BASE GASKET ALL OVER IT AS I SAID DID THE RPM CHANGE UP OR DOWN...I HAVE ALSO SEEN HUMITY AFFECT THE CAT,,BUT THATS DOWN THE ROAD...ANYWAY IF THE EGR IS LEAKING..PUSHING/SUCKING AIR THEY ARE ABOUT $45.00 A CAN OF CARB CLEANER $3.00