Toyota Tundra. Manual — part 1249

Pressure Condition in Secondary Air Injection System Case 4:

AIR SWITCHING VALVE CONDITION CHART

If the detected pressure is high, the air pump is assumed to be ON and if it alternates sharply, the ASV is
assumed to be open. The ECM locates malfunctions from the combination of pressures detected when the AIR
system is ON and OFF.

HINT:

The exhaust pulsation value is calculated in the ECM. If the calculated value exceeds a certain level, the ECM
determines that the exhaust pulsation is in the AIR system.

HINT:



In case 3, as the pressure sensor detects a slight pump operation pulsation, the detected value is not
constant. Since the pump outlet is blocked by closing the ASV, the average pressure is higher than in case
1 (approximately 20 to 30 kPa).



In case 1, the average pressure is approximately 5 to 11 kPa. The value of 1 kPa indicated in the table
above is a threshold for detecting pump malfunctions.

AIR PUMP CONDITION CHART

Air Pump

OFF

Air Switching Valve

Close

Pressure

Less than 1 kPa

Pulsation Detection

Exhaust gas pulsation detected

Detected Conditions while

AIR operating: Air pump

ON, ASV Open

Detected Conditions while

AIR not operating: Air pump

OFF, ASV Closed

ECM Determination

DTCs Output

Case 1

Case 4

Normal

-

Case 1

Case 2

ASV stuck open

P2440 or P2442

Case 1

Case 3

Air pump stuck ON

P2444 or P2446

Case 2

Case 4

Air pump stuck OFF

P2445 or P2447

Case 3

Case 4

ASV stuck closed

P2441 or P2443

Case 1

Case 1

ASV stuck open and air
pump stuck ON

P2440 and

P2444 or P2442

and P2446

Case 2

Case 2

ASV stuck open and air
pump stuck OFF

P2440 and

P2445 or P2442

and P2447

Case 3

Case 3

ASV stuck closed and
air pump stuck ON

P2441 and

P2444 or P2443

and P2446

Case 4

Case 4

ASV stuck closed and

P2441 and

P2445 or P2443

2008 Toyota Tundra

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

HINT:



If the vacuum hose between the ASV and the pressure sensor is not connected correctly, case 4 may
occur.



By using the Techstream to perform the Air Injection Check operation in the System Check, the air-fuel
ratio and the pressure in the secondary air injection system passage can be checked while the secondary
air injection system is operating. This helps technicians to troubleshoot the system when it malfunctions.
Furthermore, Pending Codes also can be checked by performing Utility/Air Injection Check/Automatic
Mode after the repair.



Read freeze frame data using the Techstream. Freeze frame data records the engine condition when
malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was
moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other
data from the time the malfunction occurred.

System Check:

The pressure in the secondary air passage can be checked using the Techstream.

a. Start the engine and warm it up.

b. Turn the ignition switch OFF.

c. Connect the Techstream to the DLC3.

d. Turn the ignition switch ON and turn the Techstream ON.

e. Enter the following menus: Powertrain/Engine and ECT/Utility/Air Injection Check/Manual Mode/AIR

PUMP 1: ON, AIR PUMP 2: ON, ASV 1: OPEN, ASV 2: OPEN and AIR PUMP 1: OFF, AIR PUMP 2:
OFF, ASV 1 CLOSE, ASV 2 CLOSE.

HINT:

When Manual Mode is selected, the Techstream initialization (atmospheric pressure measurement) is
performed automatically. The initialization takes 10 seconds. After the initialization, AP (AIR PUMP)
and ASV operation can be selected.

f. Start the engine.

g. Perform the AIR system intrusive operation while the engine is idling.

h. Check that the air pump (AIR PUMP), ASV and pressure in the AIR system passage (PRESSURE)

displayed on the Techstream indicate the conditions shown in the table below.

Standard

AIR PUMP OPERATION CHART

air pump stuck OFF

and P2447

Tester Operations

AIR PUMP

ASV

PRESSURES

(1)

PULSATIONS

(2)

AP (AIR PUMP): ON, ASV:

ON

OPEN

1 kPa or more

15 kPa or more

2008 Toyota Tundra

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

i. Turn the ignition switch OFF.

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO SECONDARY AIR INJECTION

SYSTEM DTCS)

a. Connect the Techstream to the DLC3.

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

c. Enter the following menus: Powertrain/Engine and ECT/Trouble Codes.

d. Read DTCs.

Result

RESULT CHART

OPEN

AP (AIR PUMP): OFF, ASV:

CLOSE

OFF

CLOSE

Less than 1 kPa

Less than 15 kPa

(1)

Average pumping pressure (gauge pressure). The pressure should be 1 kPa or more when the AIR
system operates.

(2)

The cumulative exhaust pulsation calculated by the ECM. If the calculated value exceeds a certain
level, the ECM determines that the exhaust pulsation is in the AIR system.

NOTE:



This Air Injection Check only allows technicians to operate the AIR
system for a maximum of 5 seconds. Furthermore, the check can
only be performed up to 4 times per trip. If the test is repeated,
intervals of at least 30 seconds are required between checks. While
AIR system operation using the Techstream is prohibited, the
Techstream display indicates the prohibition (Wait or Error).

If an Error is displayed on the Techstream during the test, stop the
engine for 10 minutes, and then try again.



Performing the Air Injection Check repetitively may cause damage to
the AIR system. If necessary, leave an interval of several minutes
between System Check operations to prevent the system from
overheating.



When performing the Air Injection Check operation after the battery
cable has been reconnected, wait for 7 minutes with the ignition
switch turned ON or the engine running.



Turn the ignition switch OFF when the Air Injection Check operation
finishes.

Display (DTC Output)

Proceed To

P2440, P2441, P2442 and/or P2443

A

P2440, P2441, P2442 and/or P2443 and P0412 and/or P0415

B

2008 Toyota Tundra

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

HINT:

If any DTCs other than P0412, P0415, P2440, P2441, P2442 and/or P2443 are output, troubleshoot
those DTCs first.

B : GO TO AIR SWITCHING VALVE INSPECTION PROCEDURE (P0412 AND P0415) (See
INSPECTION PROCEDURE )

C : GO TO DTC CHART (See DIAGNOSTIC TROUBLE CODE CHART )

A : Go to next step.

2. PERFORM ACTIVE TEST USING TECHSTREAM

a. Visual check

1. Start the engine and warm it up.

2. Turn the ignition switch OFF.

3. Disconnect the No. 2 air injection system hose.

4. Connect the Techstream to the DLC3.

5. Turn the ignition switch ON and turn the Techstream ON.

6. Enter the following menus: Powertrain/Engine and ECT/Utility/Air Injection Check/Manual

Mode/AIR PUMP 1: ON, AIR PUMP 2: ON, ASV 1: OPEN, ASV 2: OPEN.

HINT:

When Manual Mode is selected, the Techstream initialization (atmospheric pressure
measurement) is performed automatically. The initialization takes 10 seconds. After the
initialization, AP (AIR PUMP) and ASV operation can be selected.

Fig. 215: Connecting Techstream To DLC3

P2440, P2441, P2442 and/or P2443 and other DTCs (except P0412 and P0415)

C

2008 Toyota Tundra

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