Toyota Sequoia (2005). Manual — part 119
A23508
Wire Harness Side:
Canister Connector
Front View
L5
A23446
L5
–
DIAGNOSTICS
ENGINE
DI–271
465
4
Measure voltage and resistance of pump module connector.
PREPARATION:
(a)
Disconnect the L5 canister connector.
(b)
Turn the ignition switch to ON.
CHECK:
Measure the voltage and resistance of the L5 connector.
OK:
Standard:
Tester Connections
Specified Conditions
L5–4 – Body ground
Between 4.5 V and 5.5 V
L5–3 – Body ground
Between 4.5 V and 5.5 V
L5–2 – Body ground
100
Ω
or less
RESULT:
Test Results
Suspected Trouble Areas
Proceed To
Voltage and resistance within standard ranges
Open in pressure sensor circuit
A
Voltage and resistance outside standard ranges
Open in wire harness/connector (ECM – pressure sensor)
B
B
Go to step 6.
A
5
Replace charcoal canister assembly.
NEXT
Go to step 8.
6
Repair or replace wire harness and connectors.
HINT:
If the exhaust tail pipe has been removed, go to the next step before reinstalling it.
NEXT
Go to step 8.
DI–272
–
DIAGNOSTICS
ENGINE
466
7
Replace ECM (See page
).
NEXT
8
Check whether DTC output recurs.
PREPARATION:
(a)
Connect the hand–held tester to the DLC3.
(b)
Turn the ignition switch to ON and turn the tester ON.
(c)
Wait for at least 60 seconds.
CHECK:
(a)
On the tester, select the following menu items: DIAGNOSIS/ENHANCED OBD II/DTC INFO/PEND-
ING CODES.
HINT:
If no pending DTC is displayed on the tester, the repair has been successfully completed.
NEXT
Completed
–
DIAGNOSTICS
ENGINE
DI–273
467
DTC
P0455
Evaporative Emission Control System Leak
Detected (Gross Leak)
DTC
P0456
Evaporative Emission Control System Leak
Detected (Very Small Leak)
DTC SUMMARY
DTC
Monitoring Items
Malfunction Detection Conditions
Trouble Areas
Detection
Timings
Detection
Logic
P0455
EVAP gross leak
Vacuum pump creates negative pressure
(vacuum) in EVAP system and EVAP sys-
tem pressure measured. 0.02 inch leak
pressure standard is measured at the start
and at the end of the leak check.
If stabilized pressure higher than [second
0.02 inch leak pressure standard x 0.2],
ECM determines that EVAP system has
large leakage.
Fuel tank cap (loose)
Leakage from EVAP line
(Canister – Fuel tank)
Leakage from EVAP line
(Purge VSV – Canister)
Pump module
Leakage from fuel tank
Leakage from canister
While
ignition
switch
OFF
2 trip
P0456
EVAP small leak
Vacuum pump creates negative pressure
(vacuum) in EVAP system and EVAP sys-
tem pressure measured. 0.02 inch leak
pressure standard is measured at the start
and at the end of the leak check.
If stabilized pressure larger than second
0.02 inch leak pressure, ECM determines
that EVAP system has small leakage.
Same above
While
ignition
switch
OFF
2 trip
CIRCUIT DESCRIPTION
The circuit description can be found in the EVAP (Evaporative Emission) Inspection Procedure (see page
DID8A–01
B17399
Fuel Tank
Canister
Vacuum Pump: OFF
Pressure Sensor
0.02 Inch Orifice
Pump Module
Operation A: Atmospheric Pressure Measurement
Vent Valve: OFF (vent)
Operation D: Purge VSV monitor
Operation B: 0.02 Inch Leak Pressure Measurement
Negative
Pressure
Atmospheric
Pressure
Operation C: EVAP Leak Check
Air Filter
Purge VSV: OFF
OFF (vent)
ON
OFF
OFF
ON
ON (closed)
ON
ON
ON (closed)
DI–274
–
DIAGNOSTICS
ENGINE
468
MONITOR DESCRIPTION
5 hours* after the ignition switch is turned OFF, the electric vacuum pump creates negative pressure (vacu-
um) in the EVAP (Evaporative Emission) 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.
Sequence
Operations
Descriptions
Duration
–
ECM activation
Activated by soak timer, 5 hours (7 or 9.5 hours) after ignition switch turned to OFF.
–
A
Atmospheric pressure
measurement
Vent valve turned OFF (vent) and EVAP system pressure measured by ECM in order to
register atmospheric pressure.
If EVAP pressure is not between 70 kPa and 110 kPa (525 mmHg and 825 mmHg), ECM
cancels EVAP system monitor.
10 seconds
B
First 0.02 inch leak
pressure measure-
ment
In order to determine 0.02 inch leak pressure standard, vacuum pump creates negative pres-
sure (vacuum) through 0.02 inch orifice and them ECM checks if vacuum pump and vent
valve operate normally.
60 seconds
C
EVAP system pres-
sure measurement
Vent valve turned ON (closed) to shut EVAP system.
Negative pressure (vacuum) created in EVAP system, and EVAP system pressure then
measured.
Write down the measured value as it will be used in the leak check.
If EVAP pressure does not stabilize within 15 minutes, ECM cancels EVAP system monitor.
15 minutes*
D
Purge VSV monitor
Purge VSV opened and then EVAP system pressure measured by ECM.
Large increase indicates normal.
10 seconds
E
Second 0.02 inch leak
pressure measure-
ment
Leak check is performed after second 0.02 inch leak pressure standard is measured.
If stabilized system pressure higher than second 0.02 inch leak pressure standard, ECM
determines that EVAP system leaking.
60 seconds
F
Final check
Atmospheric pressure measured and then monitoring result recorded by ECM.
–
* If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст