Toyota Tundra. Manual — part 1210

Fig. 152: Monitor Description When Purge VSV Stuck Open

b. Purge VSV stuck closed

In operation D, the canister pressure sensor measures the EVAP system pressure. The pressure
measurement for the purge VSV monitor is begun when the purge VSV is turned ON (open) after
the EVAP leak check. When the measured pressure indicates an increase of 0.3 kPa-g (2.25 mmHg-
g) or more, the purge VSV is functioning normally. If the pressure does not increase, the ECM
interprets this as the purge VSV being stuck closed. The ECM illuminates the MIL and sets the
DTC (2 trip detection logic).

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

Fig. 153: Monitor Description When Purge VSV Stuck Closed

2. PURGE FLOW MONITOR

Fig. 154: EVAP Pressure During Purge Flow Monitor

The purge flow monitor consists of two monitors. The 1st monitor is conducted every time and the 2nd
monitor is activated if necessary.



The 1st monitor

While the engine is running and the purge VSV is ON (open), the ECM monitors the purge flow by
measuring the EVAP pressure change. If negative pressure is not created, the ECM begins the 2nd
monitor.

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra



The 2nd monitor

The vent valve is turned ON (closed) and the EVAP pressure is then measured. If the variation in the
pressure is less than 0.5 kPa-g (3.75 mmHg-g), the ECM interprets this as the purge VSV being stuck
closed, and illuminates the MIL and sets DTC P0441 (2 trip detection logic).

Atmospheric pressure check:

In order to ensure reliable malfunction detection, the variation between the atmospheric pressures, before
and after conduction of the purge flow monitor, is measured by the ECM.

OBD II MONITOR SPECIFICATIONS

1. Key-off Monitor

Monitor Strategy

MONITOR STRATEGY

Typical Enabling Conditions

TYPICAL ENABLING CONDITIONS

Typical Malfunction Thresholds

Required Sensors/Components

Purge VSV and canister pump module

Frequency of Operation

Once per driving cycle

Duration

Within 15 minutes (varies with fuel in tank)

MIL Operation

2 driving cycles

Sequence of Operation

None

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 2.5 mph (4 km/h)

Ignition switch

OFF

Time after key off

5 or 7 or 9.5 hours

Canister pressure sensor malfunction (P0451, P0452 and P0453)

Not detected

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)

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

TYPICAL MALFUNCTION THRESHOLDS

OBD II MONITOR SPECIFICATIONS

1. Purge Flow Monitor

Monitor Strategy

MONITOR STRATEGY

Typical Enabling Conditions

TYPICAL ENABLING CONDITIONS

Purge VSV stuck open:

-

EVAP pressure when vacuum introduction complete

Higher than reference pressure x 0.2

Purge VSV stuck closed:

-

EVAP pressure change after purge VSV ON (open)

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

Required Sensors/Components

Purge VSV and canister pump module

Frequency of Operation

Once per driving cycle

Duration

Within 10 minutes

MIL Operation

2 driving cycles

Sequence of Operation

None

Monitor runs whenever following DTCs not present

P0011 (VVT System 1 - Advance)
P0012 (VVT System 1 - Retard)
P0021 (VVT System 2 - Advance)
P0022 (VVT System 2 - Retard)
P0102 - P0103 (MAF meter)
P0110-P0113 (IAT sensor)
P0115 - P0118 (ECT sensor)
P0120 - P0223, P2135 (TP sensor)
P0125 (Insufficient ECT for Closed Loop)
P0171, P0172 (Fuel system)
P0300 - P0306 (Misfire)
P0335 (CKP sensor)
P0340 (VVT sensor)
P0351 - P0356 (Igniter)
P0451 - P0453 (EVAP press sensor)
P0500 (VSS)

Engine

Running

ECT

4.4°C (40°F) or more

IAT

4.4°C (40°F) or more

Canister pressure sensor malfunction

Not detected

Purge VSV

Not operated by scan tool

EVAP system check

Not operated by scan tool

Battery voltage

10 V or more

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra