Exhaust Gas Recirculation: Testing and Inspection

EGR System Inspection:

EGR SYSTEM INSPECTION (FEDERAL VEHICLES)

1. Disconnect the green striped vacuum hose from the throttle body and connect a hand vacuum pump to the disconnected vacuum hose.
2. While the engine is cold (coolant temperature less than 50 degrees C or 122 degrees F) run the engine at idle, apply vacuum and verify that it leaks.
3. Allow the engine to warm up (coolant temperature greater than 80 degrees C or 176 degrees F) and apply 6 kPa or 1.7 in. Hg of vacuum while the engine is at idle and verify that vacuum holds.
4. Increase vacuum to 26 kPa or 7.5 in. Hg and verify that vacuum holds and engine idle becomes unstable.

EGR System Inspection (California Only):

EGR SYSTEM INSPECTION (CALIFORNIA VEHICLES)

1. Disconnect the green striped vacuum hose from the EGR valve body and connect a hand vacuum pump using a vacuum "Tee".
2. While the engine is cold (coolant temperature less than 60 degrees C or 140 degrees F) race the engine and verify that no vacuum is present.
3. Allow the engine to warm up (coolant temperature greater than 70 degrees C or 158 degrees F) and verify that when the engine is raced vacuum rises momentarily to 14 kPa or 3.9 in. Hg.

EGR Valve Inspection (California Only):

4. Disconnect the vacuum "Tee" and connect the vacuum pump directly to the EGR valve.
5. Apply 26 kPa or 7.5in. Hg while the engine is at idle and verify that idle becomes unstable.





EGR VALVE INSPECTION

1. Remove the EGR valve from the vehicle and check for sticking, carbon deposits, or obvious damage. If necessary clean the valve with a suitable solvent.
2. Connect a hand vacuum pump to the EGR valve. Apply 67 kPa or 19.4 in. Hg of vacuum and verify that the diaphragm chamber is leak tight.
3. Apply 8 kPa or 2.4 in. Hg of vacuum and verify that air will not pass through the valve.
4. Increase vacuum to 23 kPa or 6.8 in. Hg and verify that air will pass through the valve.
5. Re-install the EGR valve and torque to 19 - 27 Nm or 14 - 20 ft. lbs.

Thermo Valve Inspection:

THERMO VALVE INSPECTION

1. Disconnect all vacuum hoses from the thermo valve.
2. Connect a hand vacuum pump to the thermo valve.
3. While the engine is cold (coolant temperature less than 50 degrees C or 122 degrees F) apply vacuum and verify that vacuum leaks.
4. Warm the engine up (coolant temperature greater than 80 degrees C or 176 degrees F) and verify that vacuum holds.

Purge Control Solenoid Valve Inspection:

EGR CONTROL SOLENOID VALVE INSPECTION

1. Disconnect the green striped vacuum hose from the solenoid valve.
2. Disconnect the harness connector.
3. Connect a hand vacuum pump to the nipple the vacuum hose was removed from.
4. Apply vacuum and verify that it holds.
5. Apply power to the EGR control solenoid valve and verify that vacuum leaks.






6. Apply power to the EGR control solenoid valve and verify that vacuum leaks.






7. Measure the resistance of the solenoid valve and verify that it is 36 - 44 ohms at 20 degrees C or 68 degrees F.