TEST
ACTION
APPLICABILITY
4
NOTE: This test may set additional DTCs. They should be disregarded.
NOTE: The Vacuum Output Hose must not be leaking or restricted for the
result of this test to be valid.
Turn the ignition off.
Disconnect the Vacuum Supply and Vacuum Output Hoses in the EGR Solenoid
vacuum connector.
Connect the Vacuum Supply Hose to the Vacuum Output Hose.
Test drive the vehicle and observe vehicle performance.
Is there a power reduction on vehicle acceleration?
All
Yes
→ Go To 5
No
→ Replace the EGR Valve.
Perform ROAD TEST VERIFICATION - VER-2.
5
Turn the ignition off.
Disconnect the vacuum hose at the EGR valve.
Connect a hand held vacuum pump to the EGR Valve.
Start the engine and allow it to idle.
Note the tone of the idling engine while slowly increasing the vacuum pump to 25
inches.
NOTE: There should be a noticeable change in engine tone as the vacuum
opens the EGR valve. There should also be a drop in MAF Sensor volts by
approximately 0.4 volt.
Does the engine tone change when vacuum is applied to the EGR Valve?
All
Yes
→ Test Complete.
No
→ Replace the EGR Valve.
Perform ROAD TEST VERIFICATION - VER-2.
224
DRIVEABILITY - DIESEL
*CHECKING THE EGR SYSTEM —
Continued