Test Description
WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers in the diagnostic procedures.
- 3
The EGR vacuum vent solenoid is normally closed. When the EGR vacuum vent solenoid is closed, it will vent to atmosphere. Therefore it should not hold vacuum with this test. - 4
The EGR valve vacuum control solenoid is normally closed. When vacuum is applied to the commanded open EGR vacuum vent solenoid it should hold vacuum. If the vacuum does not hold, then a stuck open EGR valve vacuum control solenoid is indicated.