Toyota Tundra. Manual — part 1613

-

ECM activation

Activated by soak timer 5, 7 or 9.5 hours after ignition switch
turned off.

-

A

Atmospheric
pressure
measurement

Vent valve turned OFF (vent) and EVAP system pressure
measured by ECM in order to register atmospheric pressure.
If pressure in EVAP system not between 70 kPa-a and 110
kPa-a (525 mmHg-a and 825 mmHg-a), ECM cancels EVAP
system monitor.

10

seconds

B

First reference
pressure
measurement

In order to determine reference pressure, leak detection pump
creates negative pressure (vacuum) through reference orifice
and then ECM checks if leak detection pump and vent valve
operate normally.

60

seconds

C

EVAP system
pressure
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 measured value as it will be used in leak check.
If EVAP pressure does not stabilize within 15 minutes, ECM
cancels EVAP system monitor.

15

minutes

(1)

D

Purge VSV monitor

Purge VSV opened and then EVAP system pressure measured
by ECM.
Large increase indicates normality.

10

seconds

E

Second reference
pressure
measurement

After second reference pressure measurement, leak check
performed by comparing first and second reference pressure.
If stabilized system pressure higher than second reference
pressure, ECM determines that EVAP system leaking.

60

seconds

-

Final check

Atmospheric pressure measured and then monitoring result
recorded by ECM.

-

(1)

If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

Saturday, June 19, 2010 7:34:45 PM

Page 545

© 2006 Mitchell Repair Information Company, LLC.

Fig. 241: Identifying Evaporative Emission Operation Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

P2420: Vent valve stuck open (vent)

In operation C, the vent valve turns ON (closes) and the EVAP system pressure is then measured by the ECM
using the canister pressure sensor to conduct an EVAP leak check. If the pressure does not increase when the
vent valve is open, the ECM interprets this as the vent valve being stuck open. The ECM illuminates the MIL
and stores the DTC.

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

Saturday, June 19, 2010 7:34:45 PM

Page 546

© 2006 Mitchell Repair Information Company, LLC.

Fig. 242: EVAP Pressure Graph
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

MONITOR STRATEGY

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

Saturday, June 19, 2010 7:34:45 PM

Page 547

© 2006 Mitchell Repair Information Company, LLC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

TYPICAL MALFUNCTION THRESHOLDS CONDITIONS

MONITOR RESULT

Refer to CHECKING MONITOR STATUS .

DTC P2431 SECONDARY AIR INJECTION SYSTEM AIR FLOW/PRESSURE SENSOR CIRCUIT
RANGE/PERFORMANCE BANK 1; DTC P2432 SECONDARY AIR INJECTION SYSTEM AIR
FLOW/PRESSURE SENSOR CIRCUIT LOW BANK 1; DTC P2433 SECONDARY AIR INJECTION
SYSTEM AIR FLOW/PRESSURE SENSOR CIRCUIT HIGH BANK 1; DTC P2436 SECONDARY AIR
INJECTION SYSTEM AIR FLOW/PRESSURE SENSOR CIRCUIT RANGE/PERFORMANCE BANK
2; DTC P2437 SECONDARY AIR INJECTION SYSTEM AIR FLOW/PRESSURE SENSOR CIRCUIT
LOW BANK 2; DTC P2438 SECONDARY AIR INJECTION SYSTEM AIR FLOW/PRESSURE
SENSOR CIRCUIT HIGH BANK 2

Required Sensors/Components

Purge VSV and canister pump module

Frequency of Operation

Once per driving cycle

Duration

Within 2 minutes (varies with amount of fuel in tank)

MIL Operation

2 driving cycles

Sequence of Operation

None

Monitor runs whenever following DTCs not present

P0452, P0453 (EVAP System)

EVAP key-off monitor runs when all of following conditions met -
Atmospheric pressure

70 to 110 kPa-a (525 to 825 mmHg-a)

Battery voltage

10.5 V or more

Vehicle speed

Below 4 km/h (2.5 mph)

Ignition switch

Off

Time after key off

5 or 7 or 9.5 hours

Purge VSV

Not operated by scan tool

Vent valve

Not operated by scan tool

Leak detection pump

Not operated by scan tool

Both of following conditions met before key off

Conditions 1 and 2

1. Duration that vehicle driven

5 minutes or more

2. EVAP purge operation

Performed

ECT

4.4 to 35°C (40 to 95°F)

IAT

4.4 to 35°C (40 to 95°F)

EVAP pressure change after EVAP canister vent valve ON

Less than 0.3 kPa-g (2.25 mmHg-g)

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

Saturday, June 19, 2010 7:34:45 PM

Page 548

© 2006 Mitchell Repair Information Company, LLC.