P0449 EVAP Vent Solenoid Control Circuit MalfunctionPossible Causes Setting Conditions
Vent connector is damaged (check pins for damage, and for moisture)
Vent solenoid control circuit is open, shorted to ground or to shorted to voltage
Vent solenoid Ignition circuit is open (check the TCM BATT fuse in fuse block)Vehicle Application: 2007 Chevrolet Tahoe LS 5.3L, FLEX, Vin 0, Eng Des LMG
Customer Concern: DTC P0449.
Tests/Procedures: 1. Check the TCCM-battery fuse 14 in the under hood fuse block.
2. Check for Battery Voltage (B+) at the vent solenoid pin B Red/White wire.
3. Check the White wire at the vent solenoid for a ground with the vent solenoid commanded off.
4. If the White wire has a ground with the vent solenoid commanded off, unplug the C1 connector at the Engine Control Module (ECM). If the ground is gone replace the ECM, if there is still a ground on the White wire with the ECM unplugged, check for a short to ground between the vent solenoid and the ECM.
Potential Causes: Grounded Circuit — Short to ground.
Electronic Control Module (ECM)
Power
Vent Control Solenoid
Wiring
P0449 Battery voltage is supplied to the Evaporative Emission Control System (EVAP) canister vent solenoid valve. The control module grounds the EVAP canister vent solenoid valve control circuit to close the valve by means of an internal switch called a driver. The scan tool displays the commanded state of the EVAP canister vent solenoid valve as ON or OFF. The control module monitors the status of the driver.
Diagnostic Codes: P0449
Vent solenoid has failed
ECM has failed
Key on or engine running; system voltage from 9-18v, and the ECM detected the actual and commanded state of the Vent Solenoid control circuit did not match for 5 seconds. Ignition voltage is supplied to the EVAP canister vent solenoid valve. The ECM grounds the EVAP canister vent solenoid valve control circuit to close the valve by means of an internal switch called a driver. The ECM monitors the status of the driver.
This code sets in 2 Trip(s).
This code will turn on the MIL (Malfunction Indicator Lamp)
Yes, if you do put a PCM in you will have to have it programed. Where I live, LEHIGH ACRES,FL., there is a professional tech that comes to the shop that calls him to flash the PCM right there. Times are hard, I'm sure somebody does that there in MA.
