| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. |
Circuit Description
Vapor pressure sensor and Vacuum Switching Valve (VSV) for vapor pressure sensor are used to detect faults in EVAP system.
DTC P0441 or P0446 are set if EVAP system leak is detected by ECM or if there is a malfunction in EVAP VSV, vapor pressure sensor VSV, or in vapor pressure sensor. DTC P0441 is also set if pressure in charcoal canister does not drop during purge control, or during purge cut-off, pressure in charcoal canister is low.
DTC P0446 is also set if when vapor pressure sensor is off, ECM does not sense continuity between vapor pressure sensor and charcoal canister. DTC P0446 is also set if when vapor pressure sensor is on, ECM does not sense continuity between vapor pressure sensor and fuel tank. DTC P0446 is also set if after purge cut off is on, pressure in charcoal canister is maintained at atmospheric pressure. Possible causes are
- Open Or Short In Vapor Pressure Sensor VSV Circuit
- Open Or Short In EVAP VSV Circuit
- Open Or Short Circuit In Vapor Pressure Sensor Circuit
- VSV For EVAP
- Vapor Pressure Sensor VSV
- Vapor Pressure Sensor
- Disconnected, Cracked, Damaged Or Blocked Vacuum Hose
- Charcoal Canister
Note. If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440, perform appropriate circuit test first before performing DTC P0440 test.