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:
Check for intermittent
problems
1. CHECK FOR INTERMITTENT PROBLEMS
HINT:
For use of the intelligent tester only:
Inspect the vehicle's ECM using check mode.
Intermittent problems are easier to detect with an
intelligent tester when the ECM is in check mode. In
check mode, the ECM uses 1 trip detection logic, which
is more ...
Perform monitor drive pattern
The monitor results and test values can be checked with
the OBD II scan tool or the intelligent tester. The engine
control module (ECM) monitors the emissions-related
components such as the thermostat, catalyst converter
and evaporative emissions (EVAP), and determines
whether they are function ...
System description
1. SYSTEM DESCRIPTION
(a) ABS
(Anti-lock Brake System)
The ABS helps prevent wheels from locking when
the brake is applied firmly or when braking on a
slippery surface.
(b) EBD
(Electronic Brake force Distribution)
The EBD control utilizes ABS, realizing proper
brake force distribution betw ...
