Toyota Sequoia (2005). Manual - part 157

–

DIAGNOSTICS

ENGINE

DI–423

617

MONITOR STRATEGY

P2430

Air flow/pressure sensor circuit range check
(Fluctuating)

P2431

Air flow/pressure sensor circuit rationality

Related DTCs

P2432

Air flow/Pressure sensor circuit range check
(Low voltage)

P2433

Air flow/pressure sensor circuit range check
(High voltage)

Required sensors/components

Pressure sensor

Frequency of operation

Continuous

Duration

P2430, P2432, P2433: 0.5 sec.
P2431: 5 sec.

MIL operation

P2430, P2432, P2433: Immediate
P2431: 2 driving cycles

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

It

Specification

Item

Minimum

Maximum

The monitor will run whenever these

DTCs are not present

See page 

DI–18

Starter

OFF

Time after starter turned from ON to OFF

2 sec.

–

Battery voltage

8 V

–

Ignition switch

ON

TYPICAL MALFUNCTION THRESHOLDS

Detection Criteria

Threshold

P2430:

Air pressure sensor voltage

Less than 0.1 V, or more than 4.8 V

P2432:

Air pressure sensor voltage

Less than 0.1 V

P2433:

Air pressure sensor voltage

More than 4.8 V

P2431:

Air pressure

Less than 338 mmHg (45 kPa), or more than 1013 mmHg (135 kPa)

A23557

ECM

A42
Air Pressure Sensor

VC

AIP

E2

E8

E8

E8

28

32

23

VC

AIP

E2

EB4

EB4

EB4

G–B

G–B

B–Y

B–Y

G–W

G–W

6

5

1

5 V

B17412

E8

E2

AIP

VC

B17439

Wire Harness Side:

Pressure Sensor Connector

A42

E2

AIP

VC

DI–424

–

DIAGNOSTICS

ENGINE

618

WIRING DIAGRAM

INSPECTION PROCEDURE

1

Check for open and short in harness and connector between pressure sensor
and ECM (See page 

IN–35

).

PREPARATION:
(a)

Remove the intake manifold (see page 

EM–36

).

(b)

Disconnect the A42 pressure sensor connector.

(c)

Disconnect the E8 ECM connector.

CHECK:
Measure the resistance between the wire harness side connec-
tors.
OK:

Standard:

Tester Connection

Specified Condition

VC (A42–1) – VC (E8–23)

AIP (A42–2) – AIP (E8–32)

E2 (A42–3) – AIP (E8–28)

Below 1 

Ω

VC (A42–1) or VC (E8–23)  – 

Body ground

AIP (A42–2) or AIP (E8–32)  – 

Body ground

10 k

Ω

 or higher

NG

Repair or replace harness and connector.

OK

B17434

Pressure Gauge

Pressure Sensor

–

DIAGNOSTICS

ENGINE

DI–425

619

2

Inspect pressure sensor.

PREPARATION:
(a)

Remove the intake manifold (see page 

EM–36

).

(b)

Connect the pressure gauge to the pressure sensor as
shown in the illustration.

(c)

Connect the hand–held tester to the DLC3 on the vehicle.

(d)

Turn the ignition switch ON and  push the hand–held tes-
ter main switch ON (Do not start engine).

(e)

Select the following items: DIAGNOSIS / ENHANCED
OBD II / DATA LIST / 2ND AIR PRESS.

CHECK:
Check that the pressure displayed on the hand–held tester fluc-
tuates when applying the pressure to the pressure sensor with
the pressure gauge.
OK:

Pressure fluctuates in response to the pressure ap-
plied with pressure gauge.

NG

Replace pressure sensor (See page 

EC–22

).

OK

Replace ECM (See page 

SF–80

).

DI–426

–

DIAGNOSTICS

ENGINE

620

DTC

P2444

Secondary Air Injection System Pump Stuck
ON Bank 1

DTC

P2445

Secondary Air Injection System Pump Stuck
OFF Bank 1

CIRCUIT DESCRIPTION

Refer to DTC P0412 on page 

DI–234

.

DTC No.

DTC Detection Condition

Trouble Area

P2444

Air pump stuck ON.

The secondary air pressure is more than 5 kPa (38 mmHg)
despite the ECM ordering the air pump to turn off.
(2 trip detection logic)

Short in air pump circuit

Air injection driver

Pressure sensor

Open or short in pressure sensor circuit

ECM

P2445

Air pump stuck OFF or air injection volume is insufficient.

The amount of air flow is below the criteria.
(The secondary air pressure is less than specified value de-
spite the ECM ordering the air pump turn ON.)
(2 trip detection logic)

Air pump fuse

Vacuum hose

Air pump assembly

Air injection driver

Open in air pump circuit

Air injection system piping

Pressure sensor

Open or short in pressure sensor circuit

ECM

MONITOR DESCRIPTION

P2444:
The ECM observes the pressure in the secondary air passage using the pressure sensor located on the air
switching valve in the secondary air injection system. The sensor measures the pressure in the secondary
air passage and sends a signal to the ECM.
If the pressure level from the sensor exceed a certain level despite the ECM turning off the air pump, the
ECM interprets this as a fault in the secondary air injection system and sets a DTC.
P2445:
The ECM calculates the amount of air flow in the secondary air system based on the output values of the
pressure sensor and mas air flow meter.
The ECM determines whether the amount of air flow is normal or not according to the calculated value. When
the amount of air flow is below the criteria, the ECM stores the DTC and illuminates the MIL.

DIDMU–01