EGR System Malfunction

EGR System Malfunction







INSPECTION

1. Thermosensor (ECT)
Soak the temperature sensitive part of a thermosensor in the water,and while changing the water temperature, make sure the resistance is changed as the following graph shows:







2. EVRV

1. Resistance Check
Check the resistance between the EVRV connector terminals using a circuit tester. Cold Resistance: 12 ±1 ohms







Connect battery voltage between EVRV connector terminals and make sure of the continuity between the ports.







2. Airtight Check
Apply negative pressure to the negative pressure input port as illustrated on the left. Although there is leakage, it is no problem if the negative pressure rises to -350 mmHg (-47 kpa) or more.







3. Working Check
Apply powervoltage between the terminals, there is no problem if the negative pressure does not rise when applied to the input port.

CAUTION: When measuring resistance with a circuit tester, be careful not to damage or deform the terminals

3. EGR Valve
With negative pressure applied to the diaphragm chamber, make sure that the valve is smoothly actuated to make the area between (1) and (2) ventilated.
Startup: About -100 mmHg ± 20 mmHg







Check to see if EGR valve is normally actuated under the following conditions:
QWS off (After warming up) Engine coolant temp.: 80 °C or higher