Exhaust Gas Recirculation: Testing and Inspection
EGR System Inspection (Federal):
EGR SYSTEM INSPECTION (FEDERAL VEHICLES)
1. Disconnect the vacuum hose (green stripe) from the throttle body and connect a hand vacuum pump to the disconnected hose end.
2. Plug the nipple the vacuum hose was removed from.
3. While the engine is cold (coolant temperature less than 50 degrees C or 122 degrees F) and running at idle apply vacuum and verify that vacuum leaks.
4. Warm the engine up (coolant temperature greater than 85 degrees C or 185 degrees F) and while running at idle apply 6 kPa or 1.8 in. Hg of vacuum and verify that vacuum holds.
5. Increase vacuum to 26 kPa or 7.7 in. Hg and verify that engine idle becomes unstable.
EGR System Inspection:
EGR SYSTEM INSPECTION (CALIFORNIA VEHICLES)
1. Disconnect the vacuum hose (green stripe) from the EGR valve and connect a vacuum pump with a "Tee" fitting.
2. While the engine is cold (coolant temperature less than 60 degrees C or 140 degrees F) race the engine while observing the vacuum gauge of the vacuum pump and note that there is no vacuum.
3. Allow the engine to warm up (coolant temperature greater than 70 degrees C or 158 degrees F) and race the engine again. Note that vacuum temporarily rises to 114 kPa or 3.9 in. Hg.
EGR Valve Inspection:
4. Disconnect the "Tee" fitting and connect the vacuum pump directly to the EGR valve.
5. While the engine is at idle apply 26 kPa or 7.7 in. Hg to the EGR valve and note that the engine becomes unstable.
Fig. 27 Testing EGR Valve Off The Car:
EGR VALVE INSPECTION
1. Remove the EGR valve and check it for sticking, carbon deposits, etc. If necessary clean the EGR valve with a suitable solvent.
2. Connect a hand vacuum pump to the EGR valve.
3. Apply a vacuum of 67 kPa or 19.8 in. Hg and verify that the diaphragm chamber is leak tight.
4. Apply 6 kPa or 1.8 in. Hg of vacuum to the valve and verify that air does not pass through the EGR valve.
5. Increase vacuum to 26 kPa or 7.7 in. Hg and verfy that air will pass through the EGR valve.
6. Re-install the EGR valve when testing is complete and tighten the mounting bolts to 10 - 15 Nm or 7.2 - l0 ft. lbs. for the 1.5 L engine and 15 - 22 Nm or 10 - 15.5 for the 1.6L engine.
Fig. 29 Testing The Thermo Valve (Federal):
THERMO VALVE INSPECTION (FEDERAL VEHICLES ONLY)
1. Disconnect the vacuum hoses from the thermo valve and connect a hand vacuum pump to the nipple of the thermo valve.
2. Apply vacuum and verify that when the engine is cold (coolant temperature less than 50 degrees C or 122 degrees F) and verify that vacuum leaks.
3. Allow the engine to warm up (coolant temperature greater than 80 degrees C or 176 degrees F), apply vacuum and verify that vacuum is held.
4. If it is necessary to remove the thermo valve do not apply a wrench to the resin part of the valve. Re-install the thermo valve using 3M locking sealant 4171. Torque the thermo valve to 20 - 40 Nm or 15 - 30 ft. lbs.
5. Reconnect the vacuum hoses.
Fig. 30 Testing The EGR Sensor:
EGR TEMPERATURE SENSOR INSPECTION (CALIFORNIA VEHICLES ONLY)
1. Remove the EGR temperature sensor from the vehicle.
2. Place the sensor in water.
3. Heat the water to 50 degrees C or 122 degrees F. Verify that the resistance of the sensor falls between 60 and 83k ohms.
4. Heat the water to 100 degrees C or 212 degrees F. Verify the the resistance of the sensor falls between 11 and 14k ohms.
5. When re-installing the temperature sensor tighten it to 10 - 12 Nm or 7.3 - 8.6 ft. lbs.
Fig. 32 Connecting A Vacuum Pump To The EGR Solenoid Valve (California Only):
EGR CONTROL SOLENOID VALVE INSPECTION (CALIFORNIA VEHICLES ONLY)
1. Mark and then disconnect the vacuum hoses (yellow and green stripe) from the solenoid valve.
2. Disconnnect the harness connector.
3. Connect a hand vacuum pump to the nipple the green striped hose was removed from.
4. Apply vacuum to the valve and verify that when 12 vdc is applied to the solenoid the vacuum holds.
5. Remove 12 vdc from the solenoid and verify that vacuum leaks through the valve.
Fig. 34 Testing The EGR Solenoid Valve Coil Resistance (California Only):
6. Measure the resistance of the solenoid coil and verify that the resistance falls between 36 and 44 ohms at 20 degrees C or 68 degrees F.