Code Definition
- DTC P0441: Evaporative Emission Control System Incorrect Purge Flow
- DTC P0446: Evaporative Emission Control System Malfunction
| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM connectors and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES - IMPORT article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT. |
Note. If DTC P0441, DTC P0446, DTC P0450 or DTC P0451 is output after DTC P0440 or DTC P0442, perform appropriate test first before performing DTC P0440 or DTC P0442 test.
Note. For component location, see appropriate illustration in THEORY & OPERATION article.
Circuit Description
Vapor pressure sensor, canister closed valve Vacuum Switching Valve (VSV) and pressure switching valve VSV are used to detect faults in EVAP system. DTC is set if EVAP system leak is detected or if there is a malfunction in EVAP VSV, pressure switching valve VSV or in vapor pressure sensor. Possible causes are
- Damaged, disconnected or blocked vacuum hose(s).
- Fuel tank cap is installed incorrectly.
- Defective fuel tank cap.
- Vapor pressure sensor circuit is open or shorted.
- Defective vapor pressure sensor.
- EVAP VSV circuit is open or shorted.
- Defective EVAP VSV.
- Canister closed valve VSV circuit is open or shorted.
- Defective canister closed valve VSV.
- Pressure switching valve VSV circuit is open or shorted.
- Defective pressure switching valve VSV.
- Damaged fuel tank.
- Defective charcoal canister.
- Fuel tank overfill valve cracked or damaged.
- Defective ECM.
Diagnostic Aids
Using scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.