Impala V6-3.9L (2007)
Code Tests and Associated Procedures/P Code Charts/P3401 See: Testing and Inspection/Diagnostic Trouble Code Tests and Associated Procedures/P
Code Charts/P3417 See: Testing and Inspection/Diagnostic Trouble Code Tests and Associated Procedures/P Code Charts/P3433
Mechanical System Testing
1. Connect a vacuum gage to the EVAP vacuum tube fitting on the electronic throttle body. Do not use a compound pressure and vacuum gage. The
vacuum gage on a hand held vacuum pump will work fine for this test.
2. Start the engine. Allow the engine to reach normal operating temperature.
3. With a scan tool, command each VLOM solenoid ON, one at a time. Each time a solenoid is commanded ON, you should observe a fluctuating
drop of intake manifold vacuum, and a misfire on the cylinder that was deactivated.
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If there is no fluctuating drop in engine vacuum, or the engine does not misfire, then refer to Cylinder Deactivation (Active Fuel Management)
System Compression Test. See: Engine, Cooling and Exhaust/Engine/Testing and Inspection/Component Tests and General Diagnostics
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. See: Testing and Inspection/Diagnostic Trouble Code Tests and
Associated Procedures/Verification Tests and Procedures
