Toyota Sequoia (2005). Manual - part 78

A15651

ECM

Intake Air Temp. Sensor
(Built into Mass Air Flow Meter)

5

4

Y–G

5 V

THA

22

R

E8

E8

G–W

28

E2

E1

M1

THA

E2

–

DIAGNOSTICS

ENGINE

DI–115

309

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

If DTCs related to different systems that have terminal E2 as the ground terminal are output simulta-
neously, terminal E2 may have an open circuit.

Read freeze frame data using 

the hand−held tester

. Freeze frame data records the engine conditions

when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the
vehicle was running or stopped, if the engine was warmed up or not, if the air–fuel ratio was lean or
rich, as well as other data from the time when a malfunction occurred.

DI–116

–

DIAGNOSTICS

ENGINE

310

1

Connect hand–held tester, and read value of intake air temperature.

PREPARATION:
(a)

Connect the hand–held tester to the DLC3.

(b)

Turn the ignition switch ON and push the hand–held tester main switch ON.

(c)

When using hand–held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DATA
LIST / ALL / INTAKE AIR.

CHECK:
Read the temperature value on the hand–held tester.
OK:

Same as actual intake air temperature.

RESULT:

Displayed Temperature

Proceed to

–40

°

C (–40

°

F)

A

140

°

C (284

°

F) or more

B

OK (Same as present temperature)

C

HINT:

If there is an open circuit, the hand–held tester indicates –40

°

C

 

(–40

°

F).

If there is a short circuit, the hand–held tester indicates 140

°

C (284

°

F)

 or more.

B

Go to step 4.

C

Check for intermittent problems 
(See page 

DI–11

).

A

A19549

THA

E2

ECM

2

1

Mass Air
Flow Meter

Mass Air
Flow Meter

4 5

M1

THA

E2

M1

B17441

THA

E2

THA

E2

ECM

Mass Air Flow Meter

M1

E8

–

DIAGNOSTICS

ENGINE

DI–117

311

2

Check for open in harness or ECM.

PREPARATION:
(a)

Disconnect the M1 mass air flow meter connector.

(b)

Connect terminals 4 and 5 of the mass air flow meter wire
harness side connector.

(c)

Turn the ignition switch ON.

(d)

When using hand–held tester, enter the following menu:
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / IN-
TAKE AIR.

CHECK:
Read the temperature value on the hand–held tester.
OK:

Standard: Temperature value: 140

°

C (284

°

F) or more

OK

Confirm good connection at sensor. If OK, re-
place mass air flow meter.

NG

3

Check for open in harness or ECM.

PREPARATION:
(a)

Connect terminals THA and E2 of the E8 ECM connector.

HINT:
Before checking, do a visual and contact pressure check for the
ECM connector.
(b)

Turn the ignition switch ON.

(c)

When using hand–held tester, enter the following menu:
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / IN-
TAKE AIR.

CHECK:
Read the temperature value on the hand–held tester.
OK:

Standard: Temperature value: 140

°

C (284

°

F) or more

OK

Repair or replace harness or connector.

NG

Confirm good connection at ECM. If OK, re-
place ECM (See page 

SF–80

).

A19550

THA

E2

ECM

Mass Air Flow
Meter

M1

B17442

ECM

Mass Air Flow Meter

THA

E2

M1

E8

DI–118

–

DIAGNOSTICS

ENGINE

312

4

Check for short in harness and ECM.

PREPARATION:
(a)

Disconnect the M1 mass air flow meter connector.

(b)

Turn the ignition switch ON.

(c)

When using hand–held tester, enter the following menu:
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / IN-
TAKE AIR.

CHECK:
Read the temperature value on the hand–held tester.
OK:

Standard: Temperature value: –40

°

C (–40

°

F)

OK

Replace mass air flow meter.

NG

5

Check for short in harness or ECM.

PREPARATION:
(a)

Disconnect the E8 ECM connector.

(b)

Turn the ignition switch ON.

(c)

When using hand–held tester, enter the following menu:
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / IN-
TAKE AIR.

CHECK:
Read the temperature value on the hand–held tester.
OK:

Standard: Temperature value: –40

°

C (–40

°

F)

OK

Repair or replace harness or connector.

NG

Replace ECM (See page 

SF–80

).