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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1863 (Engine Controls And Fuel - 2.4L (Lat) - DTC P0420 To DTC P2544) >> DTC P0685, P0689, or P0690 >> Circuit/System Verification

Circuit/System Verification

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
  1. With the ignition ON, engine OFF, command the powertrain relay ON and OFF several times using the scan tool output control function. You should either hear or feel the relay click with each command.
  2. With the ignition ON, engine OFF, probe both test points of each of the fuses supplied with voltage by the powertrain relay.
    • The test lamp should illuminate on at least one test point of each fuse. If the test lamp does not illuminate continue with Circuit/System Testing.
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