EGR Control System Test

NOTE: EGR system must pass CONTROL SYSTEM TEST and GAS FLOW TEST to pass BAR 90 FUNCTIONAL TEST.

VISUAL INSPECTION
1. Check condition and routing of vacuum hoses. Refer to Vehicle Emission Control Information (VECI) label, (underhood).
2. Ensure all vacuum hoses and electrical wires are clear of exhaust manifold to prevent deterioration. Due to temperature, vacuum hoses should always be a minimum of three inches from exhaust manifold.

Electric EGR Transducer (EET):

CONTROL SYSTEM TEST
1. Set parking brake, START engine and allow to reach normal operating temperature at idle.
2. Allow engine to idle in neutral for 70 seconds, then quickly accelerate engine rpm to between 2,000 and 3,000 rpm while observing groove on EGR valve stem for movement, (valve should move approximately 3 mm (1/8"). Repeat test several times to verify valve movement.
- If movement is visible, See EGR Gas Flow Test.
- If no movement is visible, perform VACUUM TO SOLENOID TEST below.

VACUUM TO SOLENOID TEST
1. Set parking brake, START engine and allow to reach normal operating temperature at idle.
2. Disconnect the hose from solenoid inlet port and connect a vacuum gauge to hose.
- If there is a vacuum of at least 15 inches Hg present, turn engine OFF, connect hose to inlet port, and perform EGR VALVE TEST below.
- If there is no vacuum present, locate and repair problem and return to CONTROL SYSTEM TEST.

EGR VALVE TEST
1. Disconnect hose from solenoid outlet port.
2. Connect a vacuum pump to hose.
3. Apply a vacuum of 10 inches Hg while observing the EGR valve stem for motion, stem should move approximately 3 mm (1/8"), and hold position for at least 30 seconds.
- If the EGR valve does not move there is an obstruction in the hose or the valve is bad. Repair or replace as needed, and return to CONTROL SYSTEM TEST.
- If the EGR valve moves but does not hold position for at least 30 seconds replace valve and return to CONTROL SYSTEM TEST.
- If the EGR valve moves, perform EGR SOLENOID TEST below.

Electric EGR Transducer (EET):

EGR SOLENOID TEST
1. Disconnect hoses from solenoid and plug ends.
2. Connect a vacuum pump to solenoid inlet port.
3. Disconnect solenoid electrical connector.
4. Using two jumper wires, energize solenoid by connecting one terminal to ground, and the other to battery positive. A "click" should be heard as voltage is applied to and taken away from solenoid.
5. Apply 15 inches Hg vacuum to inlet port.
6. Vacuum should hold with voltage applied to the solenoid, and bleed off with voltage removed.
7. Remove jumper wires, and check resistance of solenoid.
- Resistance should be 36 - 44 ohms.
8. If the solenoid failed any test, replace solenoid, and return to CONTROL SYSTEM TEST.

NOTE: If EGR system is functioning correctly, and CHECK Engine lamp indicates malfunction of EGR system, check on-board diagnostic system.