Toyota Sequoia (2005). Manual - part 107

B17411

E8

IGT8

IGT2

IGT4

IGT5

IGT6

IGT3

IGT7

IGT1

E1

(+)

(–)

(+)

(+)

(+)

(+)

(+)

(+)

(+)

E6

–

DIAGNOSTICS

ENGINE

DI–231

425

6

Disconnect ignition coil with igniter connector, and check voltage between ter-
minals IGT1 – IGT8 and E1 of ECM connector.

PREPARATION:
(a)

Disconnect the I1, I2, I3, I4, I5, I6, I7 or I8 ignition coil with
igniter connector.

(b)

Turn the ignition switch to ON.

CHECK:
Measure the voltage between terminals the E6 and E8 ECM
connectors when the engine is cranked.
OK:

Standard:

Tester Connection

Specified Condition

IGT1 (E8–8) – E1 (E6–1)

4.5 V or more

IGT2 (E8–15) – E1 (E6–1)

4.5 V or more

IGT3 (E8–11) – E1 (E6–1)

4.5 V or more

IGT4 (E8–10) – E1 (E6–1)

4.5 V or more

IGT5 (E8–13) – E1 (E6–1)

4.5 V or more

IGT6 (E8–12) – E1 (E6–1)

4.5 V or more

IGT7 (E8–14) – E1 (E6–1)

4.5 V or more

IGT8 (E8–9) – E1 (E6–1)

4.5 V or more

NG

Replace ECM (See page 

SF–80

).

OK

A21025

Wire Harness Side:

I1

I2

I3

I4

I5

I6

I7

I8

Ignition Coil with 
Igniter Connector

DI–232

–

DIAGNOSTICS

ENGINE

426

7

Check ignition coil with igniter power source circuit.

PREPARATION:
(a)

Disconnect the I1, I2, I3, I4, I5, I6, I7 or I8 ignition coil with
igniter connector.

(b)

Turn the ignition switch to ON.

CHECK:
Measure the voltage between the terminal of the wire harness
side connector and body ground.
OK:

Standard:

Tester Connection

Specified Condition

I1–1 – Body ground

I2–1 – Body ground

I3–1 – Body ground

I4–1 – Body ground

9 t 14 V

I5–1 – Body ground

9 to 14 V

I6–1 – Body ground

I7–1 – Body ground

I8–1 – Body ground

OK

Repair ignition coil with igniter.

NG

A21025

Wire Harness Side:

I1

I2

I3

I4

I5

I6

I7

I8

Ignition Coil with Igniter

A21378

Wire Harness Side:

I18

Ignition Switch

IG2

–

DIAGNOSTICS

ENGINE

DI–233

427

8

Check for open and short in harness and connector between ignition switch and
ignition coil with igniter.

PREPARATION:
(a)

Disconnect the I1, 2, I3, I4, I5, I6, I7 or I8 ignition coil with
igniter connector.

(b)

Disconnect the I18 ignition switch connector.

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

Standard:

Tester Connection

Specified Condition

Ignition coil (I1–1) – IG2 (I18–6)

Below 1 

Ω

Ignition coil (I2–1) – IG2 (I18–6)

Below 1 

Ω

Ignition coil (I3–1) – IG2 (I18–6)

Below 1 

Ω

Ignition coil (I4–1) – IG2 (I18–6)

Below 1 

Ω

Ignition coil (I5–1) – IG2 (I18–6)

Below 1 

Ω

Ignition coil (I6–1) – IG2 (I18–6)

Below 1 

Ω

Ignition coil (I7–1) – IG2 (I18–6)

Below 1 

Ω

Ignition coil (I8–1) – IG2 (I18–6)

Below 1 

Ω

Ignition coil (I1–1) or IG2 (I18–6) – 

Body ground

10 k

Ω

 or higher

Ignition coil (I2–1) or IG2 (I18–6) – 

Body ground

10 k

Ω

 or higher

Ignition coil (I3–1) or IG2 (I18–6) – 

Body ground

10 k

Ω

 or higher

Ignition coil (I4–1) or IG2 (I18–6) – 

Body ground

10 k

Ω

 or higher

Ignition coil (I5–1) or IG2 (I18–6) – 

Body ground

10 k

Ω

 or higher

Ignition coil (I6–1) or IG2 (I18–6) – 

Body ground

10 k

Ω

 or higher

Ignition coil (I7–1) or IG2 (I18–6) – 

Body ground

10 k

Ω

 or higher

Ignition coil (I8–1) or IG2 (I18–6) – 

Body ground

10 k

Ω

 or higher

NG

Repair or replace harness or connector.

OK

Replace ignition coil with igniter.

B17432

Air Pump

Pressure
Sensor

Air

Air Injection
Driver (AID)

Air Switching Valve
(ASV)(EASV)

Air Switching Valve No.2
(ASV No.2)(ASV1)

VSV for Air Injection

Control

ECM

Engine Coolant
Temp. Sensor

Mass Air Flow
Meter

Intake Air Temp.
Sensor

To Bank 2

To Bank1

Air Switching Valve No.2
(ASV No.2)(ASV2)

DI–234

–

DIAGNOSTICS

ENGINE

428

DTC

P0412

Secondary Air Injection System Air Switch-
ing Valve ”A” Circuit

CIRCUIT DESCRIPTION

The secondary air injection system pumps air to the exhaust port to accelerate the activation of the catalyst.
The secondary air injection system consists of the ECM, air pump, Air Switching Valve (ASV) (EASV), Air
Switching Valve No.2 (ASV No.2) (ASV1, 2), pressure sensor and air injection driver (AID). The Air Switching
Valve (ASV)(EASV) is an electromagnetic type and Air Switching Valve No.2 (ASV No.2)(ASV1,2) is a vacu-
um type.
 The secondary air injection system pumps pressurized air to the exhaust port by the air pump through the
ASV and ASV No.2. The ASV assists the ASV

 

No.2. The ASV No.2 also controls air supply.

The ECM sends signals to the AID, and then the AID operates the air pump and ASV. The pressure sensor
detects pressure and exhaust pulsation in the system when the system operates and when it does not oper-
ate, and sends the data to the ECM.

DTC No.

DTC Detection Condition

Trouble Area

P0412

All of the following conditions are met when engine is idling just

after cold start 

(1 trip detection logic):

(a) Air injection system does not operate (Air pump OFF and all

ASVs OFF)

(b) Air injection driver diagnostic signal duty is 40%.

Open in air switching valve drive circuit

Short between air switching valve circuit and +B circuit

Air injection driver

Air switching valve

ECM

P0412

All of the following conditions are met when engine is idling just

after cold start 

(1 trip detection logic):

(a) Air injection system operates (Air pump ON and all ASVs

ON)

(b) Air injection driver diagnostic signal duty is 40%.

Short between air switching valve circuit and body ground

Air injection driver

Air switching valve

ECM

DIDMV–01