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 

SF–80

).

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

DI–460

).

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.