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Home >> Chevrolet >> 2005 >> Epica LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 2.5L (LBK) - DTC P0404 To DTC P0662 >> DTC P0447 >> Test Description

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 2:  This step determines if a condition exists. An audible click should be heard when the EVAP canister vent valve is commanded ON. Repeat the command as necessary.
  2. 4:  This step tests the battery positive voltage circuit to the EVAP canister vent valve.
DTC P0447 Evaporative Emission (EVAP) Vent Solenoid Control Circuit Low Voltage

Step Action Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference:  Engine Control Module (ECM) Connector End Views  or  Engine Controls Connector End Views 
1 Did you perform the Diagnostic System Check - Engine Controls? Go to Step 2  Go to Diagnostic System Check - Engine Controls
2 
  1. Start the engine.
  2. Allow the engine to reach operating temperature.
  3. Observe the DTC Info. with a scan tool.
Did the DTC fail this ignition?		 Go to Step 4  Go to Step 3 
3
  1. Observe the Freeze Frame/Failure Records for this DTC.
  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 observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?		 Go to Step 4  Go to Diagnostic Aids
4 
  1. Turn OFF the ignition.
  2. Disconnect the evaporative emission (EVAP) canister vent valve harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the ignition 1 voltage circuit of the EVAP canister vent valve and the control circuit of the EVAP canister vent valve.
    5. IMPORTANT: The ECM pulses the solenoid ON and OFF for 3-5 seconds.
  5. Command the EVAP canister vent valve ON with a scan tool.
Does the test lamp illuminate or flash?		 Go to Step 5  Go to Step 6 
5 Measure the voltage from the control circuit of the EVAP canister vent valve to a good ground with a DMM.
Is the voltage between 3.6 - 4.2 V?		 Go to Step 9  Go to Step 10 
6 Connect a test lamp between the ignition 1 voltage circuit of the EVAP canister vent valve and a good ground.
Does the test lamp illuminate?		 Go to Step 7  Go to Step 8 
7
  1. Turn OFF the ignition.
  2. Disconnect the ECM.
  3. Test the control circuit of the EVAP canister vent valve for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 11  Go to Step 10 
8
    IMPORTANT: The ignition 1 voltage circuit supplies voltage to other components. Make sure you test all circuits for a short to ground or test all components for being shorted that share the ignition 1 voltage circuit.
  1. Repair the open, or short to ground in the ignition 1 voltage circuit of the EVAP canister vent valve. Refer to Wiring Repairs in Wiring Systems.
  2. Replace the fuse if necessary.
Did you complete the repair?		 Go to Step 11  -
9 Replace the EVAP canister vent valve.
Did you complete the replacement?		 Go to Step 11  -
10 Replace the ECM. Refer to Engine Control Module (ECM) Replacement .
Did you complete the replacement?		 Go to Step 11  -
11
  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 observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?		 Go to Step 2  Go to Step 11 
12 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 Go to Diagnostic Trouble Code (DTC) List System OK
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