P0456

2ZR-FE ENGINE CONTROL: SFI SYSTEM: P0455,P0456: Evaporative Emission Control System Leak Detected (Gross Leak)


DTC SUMMARY





DESCRIPTION

The description can be found in the EVAP (Evaporative Emission) System Component Tests and General Diagnostics.

INSPECTION PROCEDURE

Refer to the EVAP System Component Tests and General Diagnostics.

HINT
Unit expressions

- [kPa-a (mmHg-a)] denotes absolute pressure.
- [kPa-g (mmHg-g)] denotes gauge pressure (relative pressure).
- On the Techstream, choose the unit of measurement according to the inspection procedure.

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.





* (a) P0455: EVAP gross leak

In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system and the EVAP system pressure is measured. If the stabilized system pressure is higher than [second reference pressure x 0.2] (near atmospheric pressure), the ECM determines that the EVAP system has a large leak, illuminates the MIL and sets the DTC (2 trip detection logic).

* (b) P0456: EVAP very small leak

In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system and the EVAP system pressure is measured. If the stabilized system pressure is higher than the second reference pressure, the ECM determines that the EVAP system has a small leak, illuminates the MIL and sets the DTC (2 trip detection logic).





MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

P0455, P0456





TYPICAL MALFUNCTION THRESHOLDS

P0455 EVAP Gross Leak

P0455 EVAP Gross Leak:

P0456 EVAP Small Leak

P0456 EVAP Small Leak:

MONITOR RESULT

Refer to Checking Monitor Status Mode 6 Data.