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Home >> Cadillac >> 2006 >> STS Base, 3.6 7, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 3.6L - DTC P0342 To P0690 >> DTC P0496 >> Test Description
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Test Description

The number below refers to the step number on the diagnostic table.

  1. 3:  Removing the fuel fill cap will equalize the pressure inside the tank with atmospheric pressure. At 0 inches of H2O the FTP sensor should be near 1.5 volts. If the sensor is not, there is a concern with the sensor or related wiring.
P0496 Evaporative Emission (EVAP) System Flow During Non-Purge

Step Action Values Yes No
Schematic Reference:  Evaporative Emissions Hose Routing Diagram 
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2 Are DTCs P0443, P0451, P0452, or P0453 also set? - Go to Diagnostic Trouble Code (DTC) List - Vehicle Go to Step 3 
3 
  1. Remove the fuel fill cap.
  2. Turn ON the ignition, with the engine OFF.
  3. Monitor the fuel tank pressure (FTP) with a scan tool.
Does the scan tool indicate FTP within the specified range?		 -1.0 to +1.0 in H2O Go to Step 4  Go to DTC P0451 
4
  1. Disconnect the evaporative emission (EVAP) purge pipe from the EVAP canister purge valve.
  2. Install a hand held vacuum gage to the EVAP purge port.
  3. Disconnect the EVAP canister purge valve harness connector.
  4. Monitor vacuum on the vacuum gage.
  5. Start the engine and allow the engine to idle.
  6. Increase the engine speed to 1,200-1,500 RPM.
Does the gage indicate an increase in vacuum?		 - Go to Step 5  Go to Diagnostic Aids
5 Replace the EVAP canister purge valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement .
Did you complete the replacement?		 - Go to Step 6  -
6
  1. Clear the DTCs with a scan tool.
  2. Turn off the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the conditions for Running the DTC. You may also operate the vehicle within the conditions that you observe from the Freeze Frame failure records.
Did the DTC fail this ignition?		 - Go to Step 3  Go to Step 7 
7 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List - Vehicle System OK
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