FixVault

Conditions for Clearing the MIL/DTC

DTC P0449

Step Action Yes No
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) 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 the scan tool.
Do you hear or feel a click from the EVAP canister vent solenoid valve when 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 battery positive voltage circuit of the EVAP canister vent solenoid valve with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors .
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 battery positive voltage circuit of the EVAP canister vent solenoid valve.
  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 an open or short to voltage. Refer to Circuit Testing and 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 Circuit Testing and 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 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 battery positive voltage circuit. Refer to Circuit Testing and 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.
Did you complete the replacement?
Go to Step 14  -
13 Replace the powertrain control module (PCM). 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.
Are there any DTCs that have not been diagnosed?
Go to Diagnostic Trouble Code (DTC) List - Vehicle System OK