EGR Valve for MAN

The exhaust gas recirculation system (hereinafter referred to as EGR) consists of an ECR valve, an EGR vacuum control valve, an EGR control solenoid valve, a controller (ECM/PCM) and an EGR valve lift sensor, as shown in Figure 1. The exhaust gas recirculation system combined with the three-way catalyst can effectively reduce the NOx content in the emission pollution gas. Because there are two conditions for NOx generation: one is high temperature, the other is oxygen, so EGR is not working in all conditions, but: (1) Low speed, when the water temperature is lower than 50 ° C, the exhaust gas does not cycle to prevent the occurrence of stall; ② High-speed, medium load generally has the conditions to produce NOx, waste air valve put into work, control the pollution value of NOx emissions.

Fault detection and diagnosis of EGR system

2.1 Check whether the exhaust gas recirculation system is blocked

2.1.1 Check and clean the exhaust gas recirculation hole of the intake manifold with gasoline.

2.1.2 Check whether the vacuum hose is damaged, whether the joint is loose, air leakage, etc.

2.1.3 Check and clean the exhaust gas recirculation valve with carburetor cleaner or replace the exhaust gas recirculation valve.

2.2 Detection of circuit and components of exhaust gas recirculation system