P2401

2TR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P043E,P043F,P2401,P2402,P2419: Evaporative Emission System Leak Detection Reference Orifice Low Flow


DTC SUMMARY





HINT
The reference orifice is located inside the canister pump module.

DESCRIPTION

The description can be found in the EVAP (Evaporative Emission) System EVAP System.

MONITOR DESCRIPTION

5 hours* after the ignition switch is turned OFF, the leak detection pump creates negative pressure (vacuum) in the EVAP system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.

HINT
*: If the engine coolant temperature is not below 35°C (95°F) 5 hours after the ignition switch is turned OFF, the monitor check starts 2 hours later. If it is still not below 35°C (95°F) 7 hours after the ignition switch is turned OFF, the monitor check starts 2.5 hours later.





*: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.





The leak detection pump creates negative pressure through the reference orifice. When the system is normal, the EVAP pressure is between 724 to 752 mmHg* and saturated within a minute. If not, the ECM interprets this as a malfunction. The ECM will illuminate the MIL and set a DTC if this malfunction is detected in consecutive drive cycles.

*: Typical value.





MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





1. Key-off monitor sequence 1 to 8

1. Atmospheric pressure





2. First reference pressure





3. Vent valve stuck closed check





4. Vacuum introduction and leak





5. Purge VSV stuck closed check





6. Second reference pressure measurement





7. Leak check





8. Atmospheric pressure





HINT
"Saturated" indicates that the EVAP pressure change is less than 0.12 kPa (0.9 mmHg) in 30 seconds.

TYPICAL MALFUNCTION THRESHOLDS





MONITOR RESULT

Refer to detailed information on Checking Monitor Status Mode 6 Data.

INSPECTION PROCEDURE

Refer to the EVAP Inspection Procedure EVAP System.