EGR Control Solenoid: Testing and Inspection

EGR Solenoid Circuit:

To test the EGR Solenoid Valve, proceed as follows.
Turbo: Located on the left inner fender, near the firewall.
Non-turbo: Located on the firewall, near the battery.

EGR Vacuum Delivery Test:

COMPONENT TEST
1. Disconnect the green striped vacuum hose from the EGR valve and connect a hand vacuum pump through a vacuum "Tee".
2. While the engine is cold (coolant temperature less than 20 degrees C or 68 degrees F) race the engine and verify that vacuum is not present.
3. Allow the engine to warm up (coolant temperature greater than 70 degrees C or 158 degrees F).
4. Race the engine and verify that vacuum increases to 100 mm Hg or 3.9 in. Hg or more.

EGR Valve Inspection:

5. Disconnect the vacuum "Tee" and connect the vacuum pump directly to the EGR valve.
6. Using the vacuum pump apply 215 mm Hg or 8.5 in. Hg of vacuum while the engine is at idle and verify that idle becomes unstable.

EGR Source Test:

7. Disconnect the vacuum hose from the EGR port on the throttle body and connect a hand vacuum pump to the fitting.
8. Start the engine and confirm that vacuum increases as engine speed increases. (if it doesn't, the throttle chamber may be restricted).

EGR Voltage Test:

9. Disconnect the yellow/green striped hose from the solenoid valve and connect a hand vacuum pump to the fitting.
10. Disconnect the electrical connector.
11. Apply battery Voltage to the electrical connectors as shown.
12. Apply vacuum to the solenoid with the pump and note the results.
a. Vacuum should hold when Voltage is applied.
b. Vacuum should NOT hold when NO Voltage is applied.

EGR Resistance Test:

13. Using an ohm meter check the resistance across the solenoid terminals.

Resistance:
36 - 44 Ohms @ 68° F.


HARNESS TEST
1. Disconnect the EGR solenoid connector and turn the key to the ON position.
2. Using a Voltmeter, measure the power supply Voltage between the harness connector terminal 1 and ground.

Voltage:
System Voltage.

3. Turn the key OFF and disconnect the negative battery cable.
4. Using an Ohmmeter, check for continuity between the ECU harness connector terminal 53 and and solenoid connector 2.

Continuity:
Should exist.

5. Disconnect the ECU connector. Using an Ohmmeter, check for continuity between the ECU harness connector terminal 53 and ground.

Continuity:
Should not exist.

6. Using an Ohmmeter, check for continuity between the solenoid connector terminal 2 and ground.

Continuity:
Should not exist.



If any of the previous tests produce unsatisfactory results, the harness will need to be repaired or replaced. Once repairs have been completed, clear the trouble codes and road test the vehicle to confirm that the repair has corrected the problem and the code doesn't return.
If the trouble code returns, it is possible that there is an intermittent failure of the component or the ECU. Check for looseness at all harness junctions and test for an intermittent failure.