DTC P1449: Evaporative Emission System Vent Shut OFF Valve Malfunction (stuck in Closed Position)
Fig. 391: DTC P1449: Evaporative Emission System Vent Shut OFF Valve Malfunction (Stuck In Closed Position) - System Wiring Diagram
Courtesy of SUZUKI OF AMERICA CORP.
The evaporative (EVAP) emission system includes the following components:
EVAP emission vent solenoid.
Fuel tank pressure sensor.
Fuel pipes and hoses.
Fuel vapor lines.
EVAP emission canister.
EVAP emission canister purge valve.
EVAP emission service port.
The EVAP emission system is checked by applying vacuum to the EVAP emission system and monitoring for a vacuum decay. The engine control module (ECM) monitors the vacuum level through the fuel tank pressure sensor signal.
At the appropriate time, the EVAP emission canister purge valve and the EVAP emission vent solenoid are turned ON, allowing the engine to draw a small vacuum on the entire EVAP emission system. After the desired vacuum level has been achieved, the EVAP emission canister purge valve is turned OFF, sealing the system.
Conditions for Setting the DTC
FTP raw value is less than -30 hPa.
Action Taken When the DTC Sets
The Malfunction Indicator Lamp (MIL) will illuminate.
The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers.
A history DTC is stored.
Conditions for Clearing the MIL/DTC
The MIL will turn off at the end of 3 consecutive ignition cycles in which the diagnostic runs without a fault.
A history DTC will clear after 40 consecutive warm-up cycles without a fault.
DTC(s) can be cleared by using the scan tool.
Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If the DTC cannot be duplicated, the information included in the Freeze Frame and/or Failure Records data can be useful in determining how many miles since the DTC set. The Fail Counter and the Pass Counter can also be used to determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature, etc.) That were noted. This will isolate when the DTC failed.
Friday, April 30th, 2010 AT 5:24 AM