LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chevrolet >> 2006 >> SSR Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 6.0L - DTC P0449 To DTC P1682 >> DTC P0449 >> Test Description
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test Description

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

  1. 2:  A click should be heard or felt when the EVAP canister vent solenoid valve operates. Be sure that both the ON and the OFF states are commanded. Repeat the commands as necessary.
  2. 5:  This step verifies that the control module is providing ground to the EVAP canister vent solenoid valve.
  3. 6:  This step tests if the EVAP canister vent solenoid valve control circuit is grounded.
DTC P0449

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 - Vehicle? Go to Step 2  Go to Diagnostic System Check - Vehicle
2 
  1. Turn ON the ignition, with the engine OFF.
  2. Command the evaporative emission (EVAP) canister vent solenoid valve ON and OFF with a scan tool.
Do you hear or feel a click from the EVAP canister vent solenoid valve when it is commanded ON and OFF?		 Go to Step 3  Go to Step 4 
3
  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Turn ON the ignition, with the engine OFF.
  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 Testing for Intermittent Conditions and Poor Connections
4
  1. Turn OFF the ignition.
  2. Disconnect the EVAP canister vent solenoid valve.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition 1 voltage circuit of the EVAP canister vent solenoid valve with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp .
Does the test lamp illuminate?		 Go to Step 5  Go to Step 11 
5 
  1. Connect a test lamp between the control circuit of the EVAP canister vent solenoid valve and the ignition 1 voltage circuit of the EVAP canister vent solenoid valve. Refer to Troubleshooting with a Test Lamp .
  2. Command the EVAP canister vent solenoid valve ON and OFF with a scan tool.
Does the test lamp turn ON or OFF with each command?		 Go to Step 9  Go to Step 6 
6  Does the test lamp remain illuminated with each command? Go to Step 8  Go to Step 7 
7 Test the control circuit for a short to voltage or an open. Refer to Circuit Testing and to Wiring Repairs .
Did you find and correct the condition?		 Go to Step 14  Go to Step 10 
8 Test the control circuit for a short to ground. Refer to Testing for Short to Ground and to Wiring Repairs .
Did you find and correct the condition?		 Go to Step 14  Go to Step 10 
9 Test for an intermittent and for a poor connection at the EVAP canister vent solenoid valve. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs .
Did you find and correct the condition?		 Go to Step 14  Go to Step 12 
10 Test for an intermittent and for a poor connection at the control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 14  Go to Step 13 
11
  1. Repair the open or short to ground in the ignition 1 voltage circuit. Refer to Circuit Testing and to Wiring Repairs .
  2. Replace the fuse if necessary.
Did you complete the repair?		 Go to Step 14  -
12 Replace the EVAP canister vent solenoid valve. Refer to Evaporative Emission (EVAP) Canister Vent Solenoid Valve Replacement .
Did you complete the replacement?		 Go to Step 14  -
13 Replace the engine control module (ECM). Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 Go to Step 14  -
14
  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 15 
15 Observe the Capture Info with a scan tool.
Have any DTCs not been diagnosed?		 Go to Diagnostic Trouble Code (DTC) List - Vehicle System OK
scientia non olet · About LEMON Manuals