Toyota Sienna Service Manual: Evaporative Emission Control System Leak Detected
DTC P0455 Evaporative Emission Control System Leak Detected (Gross Leak)
DTC P0456 Evaporative Emission Control System Leak Detected (Very Small Leak)
DTC SUMMARY
DESCRIPTION
The circuit description can be found in the EVAP (Evaporative Emission) System.
INSPECTION PROCEDURE
Refer to the EVAP System.
MONITOR DESCRIPTION
5 hours*1 after the ignition switch is turned off, the electric vacuum pump creates negative pressure (vacuum) in the EVAP (Evaporative Emission) system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.
HINT: *1: If the engine coolant temperature is not below 35C (95F) 5 hours after the ignition switch is turned off, the monitor check starts 2 hours later. If it is still not below 35C (95F) 7 hours after the ignition switch is turned off, the monitor check starts 2.5 hours later.
*2: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.
- P0455: EVAP (Evaporative Emission) gross leak
In operation C, the vacuum 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 0.02 inch leak pressure standard 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). - 2. P0456: EVAP very small leak
In operation C, the vacuum 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 0.02 inch leak pressure standard, 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
Key-off monitor sequence 1 to 8
1. Atmospheric pressure measurement
2. First reference pressure measurement
3. EVAP canister vent valve close stuck check
4. Vacuum introduction
5. EVAP canister purge valve close stuck check
6. Second reference pressure measurement
7. Leak check
8. Atmospheric pressure measurement
TYPICAL MALFUNCTION THRESHOLDS
P0455: EVAP gross leak
P0456: EVAP 0.02 inch leak
MONITOR RESULT
Refer to CHECKING MONITOR STATUS
Evaporative Emission Control System Pressure
DTC P0450 Evaporative Emission Control System Pressure
Sensor / Switch
DTC P0451 Evaporative Emission Control System Pressure
Sensor Range / Performance
DTC P0452 Evaporative Emission Control Syst ...
Vehicle Speed Sensor "A"
DTC P0500 Vehicle Speed Sensor "A"
DESCRIPTION
The speed sensor detects the wheel speed and sends the appropriate signals to
the skid control ECU.
The skid control ECU converts these ...
Other materials:
Engine Coolant Temperature / Intake Air Temperature Correlation
DESCRIPTION
The ECM calculates the difference between the readings of the coolant
temperature sensor and intake air
temperature sensor. If the difference is greater than 20°C (68°F), the ECM will
judge this as a malfunction
and will set this DTC.
HINT:
Waiting is required t ...
Operation flow
HINT:
Perform troubleshooting in accordance with the
procedures below. The following is an outline of basic
troubleshooting procedures. Confirm the troubleshooting
procedures for the circuit you are working on before
beginning troubleshooting.
VEHICLE BROUGHT TO WORKSHOP
CUSTOMER PR ...
Removal
1. REMOVE ENGINE AND TRANSAXLE
HINT:
(See page EM-26)
2. REMOVE AUTOMATIC TRANSMISSION WITH
TRANSFER
HINT:
(See page AX-164)
3. REMOVE NO. 1 TRANSFER CASE PLUG
(a) Remove the No. 1 transfer case plug.
(b) Remove the No. 1 gasket from the transfer case No.
1 plug.
4. REMOVE NO. 2 T ...
