Toyota Tundra. Manual — part 1377

b. Turn the ignition switch to ON and turn the Techstream ON.

c. Clear DTCs (see DTC CHECK/CLEAR ).

d. Shuffle arrangement of the ignition coils with igniters (among No. 1 to No. 8 cylinders).

e. Perform a simulation test.

f. Check DTCs displayed on the Techstream.

Result

RESULT REFERENCE

B : REPLACE IGNITION COIL ASSEMBLY . (See IGNITION COIL SPARK PLUG ).

A : REPLACE ECM . (See REMOVAL).

DTC P0412 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE "A" CIRCUIT; DTC
P0415 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE "B" CIRCUIT

DESCRIPTION

The Secondary Air Injection (AIR) system consists of an air pump, the Air Switching Valve (ASV), a pressure
sensor, the Air Injection Control Driver (AID) and the ECM. For a short time after cold engine starts, the AIR
system pumps secondary air to the exhaust port of the cylinder head to purify the exhaust emissions. The
secondary air is supplied by the air pump and is pumped to the exhaust port through the ASV.

The AID drives the ASV and the air pump according to command signals transmitted by the ECM. The pressure
sensor detects the pressure in the secondary air passage when the AIR system is ON and OFF, and transmits a
pressure signal to the ECM.

The AID is not only equipped to drive the pump and valve, but also with a diagnosis function to detect
malfunctions in the AIR system circuit.

HINT:

As a large current is required to drive the air pump and ASV, an AID is installed to this system.

NOTE:

Do not shuffle the connectors.

Result

Proceed To

Same DTC is output

A

Different ignition coil DTC is output

B

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

Fig. 140: Secondary Air Injection System Diagram

DTC DETECTION CONDITION AND TROUBLE AREA

MONITOR DESCRIPTION

The Air Injection Control Driver (AID) detects open and short circuits according to the voltages of the air pump

DTC

Code

DTC Detection Condition

Trouble Area

P0412
P0415

After cold engine starts, all of following conditions met (1
trip detection logic):

a. Secondary Air Injection (AIR) system not operating

(air pump OFF, Air Switching Valve [ASV] OFF)

b. Diagnostic signal from Air Injection Control Driver

(AID) 40%

c. Battery voltage 8 V or higher



Open in ASV drive circuit



AID



ASV



ECM

P0412
P0415

After cold engine starts, all of following conditions met (1
trip detection logic):

a. Secondary Air Injection (AIR) system operating (air

pump ON, Air Switching Valve [ASV] ON)

b. Diagnostic signal from Air Injection Control Driver

(AID) 40%

c. Battery voltage 8 V or higher



Short between ASV drive
circuit and body ground



AID



ASV



ECM

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

terminal (VP) and the Air Switching Valve (ASV) terminal (VV), and transmits diagnostic information as a
signal to the ECM.

For a short time after cold engine starts, the ECM transmits command signals to the AID to drive the air pump
and ASV.

The AID transmits an ASV malfunction signal to the ECM if either of the following conditions is met:



The voltage at the AID terminal relating to the ASV is low despite the AID receiving command signals
from the ECM to drive the ASV.



The voltage at the AID terminal relating to the ASV is high despite the AID receiving no command
signals from the ECM to drive the ASV.

The ECM sets the DTC based on diagnostic signals from the AID.

MONITOR STRATEGY

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

Case 1:

TYPICAL ENABLING CONDITIONS - CASE 1

Related DTCs

P0412: Secondary air injection system air switching valve circuit
range check (bank 1)
P0415: Secondary air injection system air switching valve circuit
range check (bank 2)

Required Sensors/Components
(Main)

Air injection control driver

Required Sensors/Components
(Related)

Air switching valve

Frequency of Operation

Once per drive cycle

Duration

3 seconds

MIL Operation

Immediate

Sequence of Operation

None

Monitor runs whenever following DTCs not present

-

Secondary air injection pump

Operating

Secondary air injection switching valve

Operating

Battery voltage

8 V or higher

Ignition switch

ON

Time after ignition switch off to ON

0.5 seconds or more

Starter

OFF

Time after starter turned from ON to OFF

0.5 seconds or more

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

Case 2:

TYPICAL ENABLING CONDITIONS - CASE 2

TYPICAL MALFUNCTION THRESHOLDS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

COMPONENT OPERATING RANGE

WIRING DIAGRAM

Monitor runs whenever following DTCs not present

-

Secondary air injection pump

Not operating

Secondary air injection switching valve

Not operating

Battery voltage

8 V or higher

Ignition switch

ON

Time after ignition switch off to ON

0.5 seconds or more

Starter

OFF

Time after starter turned from ON to OFF

0.5 seconds or more

Diagnostic signal duty ratio from air injection control driver

31% or more, and 48% or less

Diagnostic signal duty ratio from air injection
control driver

70% or more, and 90% or less when secondary air
injection system operating.
0% when secondary air injection system not operating.

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra