Toyota Tundra Service Manual: Secondary Air Injection System Switching Valve Stuck Open Bank1 (P2440-P2443)

DESCRIPTION

Refer to DTC P0412 (See page ).

HINT:

Air switching valve normal operation:

When the Air Switching Valve (ASV) is open, exhaust gas pulsation occurs in the secondary air passage.

When the ASV is closed, exhaust gas pulsation does not occur in the secondary air passage.

MONITOR DESCRIPTION

The ECM monitors the pressure in the secondary air passage using the pressure sensor connected to the ASV of the Secondary Air Injection (AIR) system.

If either of the following conditions occurs, the ECM interprets it as a malfunction of the AIR system, and illuminates the MIL and stores a DTC:

• Exhaust gas pulsation is detected by the pressure sensor despite the ECM commanding the ASV to close.
• Exhaust gas pulsation is not detected by the pressure sensor despite the ECM commanding the ASV to open.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

MONITOR RESULT

Refer to Checking Monitor Status (See page ).

CONFIRMATION DRIVING PATTERN

NOTICE:

• This Secondary 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 ERROR is displayed on the Techstream during the test, stop the engine for 10 minutes, and then try again.

• Performing the Secondary Air Injection Check repeatedly 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 Secondary Air Injection Check operation after the battery cable has been reconnected, wait for 7 minutes with the ignition switch turned to ON or the engine running.
• Turn the ignition switch off when the Secondary Air Injection Check operation finishes.

1. Start the engine and warm it up.
2. Turn the ignition switch off.
3. Connect the Techstream to the DLC3.
4. Turn the ignition switch to ON.
5. Turn the Techstream on.
6. Clear DTCs (if set) (See page ).
7. Turn the ignition switch off and wait for at least 30 seconds.
8. Turn the ignition switch to ON and turn the Techstream on.
9. Enter the following menus: Powertrain / Engine and ECT / Utility / Secondary Air Injection Check / Automatic Mode.
10. Start the engine after the Techstream initialization is finished.
11. Perform the System Check operation by pressing ENTER (Next).
12. Perform the following to confirm the AIR system pending codes: Press ENTER (Exit).
13. Check for pending DTCs.

    OK:

    No pending DTC is output.

14. After the "Secondary air injection check" is completed, check for All Readiness by entering the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
15. Input the DTC: P2440, P2441, P2442 or P2443.
16. Check the DTC judgment result.

    Tester Display	Description
    NORMAL	DTC judgment completed System normal
    ABNORMAL	DTC judgment completed System abnormal
    INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
    N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
17. If the test result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs (See page ).

    HINT:

    • If no permanent DTC is output, the system is normal.
    • If a permanent DTC is output, the system is malfunctioning.
18. Turn the ignition switch off.

WIRING DIAGRAM

Refer to DTC P0412 (See page ).

CAUTION / NOTICE / HINT

HINT:

• Bank 1 refers to the bank that includes the No. 1 cylinder*.

  *: The No. 1 cylinder is the cylinder which is farthest from the transmission.

• Bank 2 refers to the bank that does not include the No. 1 cylinder.

HINT:

Determination by ECM monitoring:

The ECM locates malfunctions in the Secondary Air Injection (AIR) system by detecting the pressure in the AIR passage between the air pump and Air Switching Valve (ASV) and stores a DTC. Soon after a cold engine start, the monitor runs for a short time while the AIR system is both ON and OFF. The ECM detects both the pressure and the exhaust pulsation and compares them.

The following 8 patterns are AIR system pressure conditions in the AIR system passage.

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 and 7, 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 18 to 25 kPa).
• In case 1, the average pressure is approximately 3 to 11 kPa. The value of 1.9 kPa indicated in the table above is a threshold for detecting pump malfunctions.

HINT:

• By using the Techstream to perform the Secondary 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 / Secondary 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.
  1. Start the engine and warm it up.
  2. Turn the ignition switch off.
  3. Connect the Techstream to the DLC3.
  4. Turn the ignition switch to ON.
  5. Turn the Techstream on.
  6. Enter the following menus: Powertrain / Engine and ECT / Utility / Secondary Air Injection Check / Manual Mode / AIR PUMP 1: ON, ASV1: OPEN, AIR PUMP 2: ON, ASV2: OPEN and AIR PUMP 1: OFF, ASV1 CLOSE, AIR PUMP 2: OFF, ASV2 CLOSE.

     HINT:

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

  7. Start the engine.
  8. Perform the AIR system forced operation while the engine is idling.
  9. 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:

     Tester Operation	Air Pump	ASV	Pressure*1	Pulsation*2
     AIR PUMP: ON, ASV: OPEN	ON	OPEN	1.9 kPa or more	18 kPa or more
     AIR PUMP: OFF, ASV: CLOSE	OFF	CLOSE	Less than 3.0 kPa	Less than 25 kPa

     *1: Average pumping pressure (gauge pressure). The pressure should be 1.9 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.

  10. Turn the ignition switch off.

      NOTICE:

      • This Secondary 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 ERROR is displayed on the Techstream during the test, stop the engine for 10 minutes, and then try again.

      • Performing the Secondary Air Injection Check repeatedly 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 Secondary Air Injection Check operation after the battery cable has been reconnected, wait for 7 minutes with the ignition switch turned to ON or the engine running.
      • Turn the ignition switch off when the Secondary Air Injection Check operation finishes.

PROCEDURE

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(e) Read DTCs.

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 ASSEMBLY INSPECTION PROCEDURE (P0412 AND P0415)

C

GO TO DTC CHART

A

(a) Disconnect the air pump assembly (for bank 1 or Bank 2) connector.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON and turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT/ Active Test / Activate the Air Pump Heater.

(e) Measure the voltage according to the value(s) in the table below.

(f) Reconnect the air pump assembly (for bank 1 or Bank 2) connector.

NG

GO TO STEP 4

OK

(a) Inspect the air pump assembly (for bank 1 or bank 2) (See page ).

NG

REPLACE AIR PUMP ASSEMBLY (FOR BANK 1 OR BANK 2)

OK

NG

REPLACE AIR PUMP HEATER (AI-HTR) RELAY

OK

(a) Remove the air pump heater (AI HTR) relay.

(b) Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition AI HTR relay terminal 5 - Body ground Always 11 to 14 V

(c) Reinstall the air pump heater (AI-HTR) relay.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

(a) Remove the air pump heater (AI HTR) relay.

(b) Disconnect the air pump assembly (for bank 1 or bank 2) connector.

(c) Measure the resistance according to the value(s) in the table below.

(d) Reinstall the air pump heater (AI HTR) relay.

(e) Reconnect the air pump assembly (for bank 1 or bank 2) connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

(a) Inspect the air pump assembly (for bank 1 or bank 2) (See page ).

NG

REPLACE AIR PUMP ASSEMBLY (FOR BANK 1 OR BANK 2)

OK

(a) Visual check:

(1) Start the engine and warm it up.

(2) Turn the ignition switch off.

(3) Disconnect the No. 1 air hose.

(4) Connect the Techstream to the DLC3.

(5) Turn the ignition switch to ON.

(6) Turn the Techstream on.

(7) Enter the following menus: Powertrain / Engine and ECT / Utility / Secondary Air Injection Check / Manual Mode / AIR PUMP 1: ON, ASV1: OPEN, AIR PUMP 2: ON, ASV2: 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 and ASV operation can be selected.

(8) Start the engine.

(9) Perform the AIR system forced operation while the engine is idling.

(10) Place your hand near the air switching valve port and check that the exhaust gas pressure pulsates when the ASV is turned ON.

CAUTION:

To avoid the danger of being burned by the exhaust gas, bring your hand close to the valve port slowly.

(11) Enter the following menus: Powertrain / Engine and ECT / Utility / Secondary Air Injection Check / Manual Mode / AIR PUMP 1: ON, ASV1: OPEN, AIR PUMP 2: ON, ASV2: OPEN and AIR PUMP 1: ON, ASV1: CLOSE, AIR PUMP 2: ON, ASV2: CLOSE.

(12) Check that the exhaust gas does not pulsate when the ASV is turned OFF.

(13) Turn the ignition switch off.

NOTICE:

• This Secondary 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 ERROR is displayed on the Techstream during the test, stop the engine for 10 minutes, and then try again.

• Performing the Secondary Air Injection Check repeatedly 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 Secondary Air Injection Check operation after the battery cable has been reconnected, wait for 7 minutes with the ignition switch turned to ON or the engine running.
• Turn the ignition switch off when the Secondary Air Injection Check operation finishes.

OK:

(b) Other inspection method:

The ASV operation can be confirmed by checking the cumulative pressure pulsation* provided in the System Check.

Perform System Check operation under Manual Mode.

*: 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.

(1) Start the engine and warm it up.

(2) Turn the ignition switch off.

(3) Connect the Techstream to the DLC3.

(4) Turn the ignition switch to ON.

(5) Turn the Techstream on.

(6) Enter the following menus: Powertrain / Engine and ECT / Utility / Secondary Air Injection Check / Manual Mode / AIR PUMP 1: ON, ASV1: OPEN, AIR PUMP 2: ON, ASV2: OPEN and AIR PUMP 1: OFF, ASV1: CLOSE, AIR PUMP 2: OFF, ASV2: CLOSE.

(7) Start the engine after the Techstream initialization is finished.

(8) Perform the AIR system forced operation while the engine is idling.

(9) Check that the air-fuel ratio and pressure in the secondary air injection system passage (PULSATION) displayed on the Techstream indicate the conditions shown in the table below.

(10) Turn the ignition switch off.

OK:

Reference:

If the air pump operation is confirmed as normal (See page ), the air-fuel ratio detected in front of the three-way catalytic converter changes in response to the secondary air pumped into the exhaust port when the air pump operates.

B

GO TO STEP 16

A

(a) Check that the No. 2 and No. 3 air tubes are securely connected to both the exhaust manifold and the air switching valve assembly.

(b) Inspect the air tube for blockages and damage.

OK:

No blockages in or damage to air tubes.

NG

REPLACE AIR TUBE

OK

(a) Inspect the air switching valve (for bank 1) (See page ).

(b) Inspect the air switching valve (for bank 2) (See page ).

B

REPLACE AIR SWITCHING VALVE ASSEMBLY (FOR BANK 1)

C

REPLACE AIR SWITCHING VALVE ASSEMBLY (FOR BANK 2)

A

(a) Disconnect the air injection control driver (AID) (for bank 1 or bank 2) connectors.

(b) Turn the ignition switch to ON.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

(d) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

NG

REPAIR OR REPLACE AIR INJECTION CONTROL DRIVER POWER SOURCE CIRCUIT

OK

(a) Disconnect the ECM connectors.

(b) Disconnect the air injection control driver (AID) (for bank 1 or bank 2) connectors.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

(a) Disconnect the air injection control driver (AID) (for bank 1 or bank 2) connector.

(b) Connect terminals DI and SIV or DI2 and SIV2 of the wire harness connector for the AID.

(c) Connect the Techstream to the DLC3.

(d) Turn the ignition switch to ON and turn the Techstream on.

(e) Enter the following menus: Powertrain / Engine and ECT / Utility / Secondary Air Injection Check / Manual Mode / AIR PUMP 1: ON, ASV 1: OPEN, AIR PUMP 2: ON, 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, AIR PUMP and ASV operation can be selected.

(f) Start the engine.

(g) Perform the AIR system forced operation while the engine is idling.

(h) Measure the voltage between the SIV and E or SIV2 and E2 terminals of the ECM connector when the AIR system is ON and OFF.

(i) Turn the ignition switch off.

NOTICE:

• Performing Secondary Air Injection Check repeatedly may cause damage to the secondary air injection system. If it is necessary to repeat the check, leave an interval of several minutes between System Check operations to prevent the system from overheating.
• When performing the Secondary Air Injection Check operation after the battery cable has been reconnected, wait for 7 minutes with the ignition switch ON or the engine running.
• Turn the ignition switch off when the Secondary Air Injection Check operation finishes.

Standard Voltage:

(j) Connect terminals DI and SIP or DI2 and SIP2 of the wire harness connector for the AID.

(k) Connect the Techstream to the DLC3.

(l) Turn the ignition switch to ON and turn the Techstream on.

(m) Enter the following menus: Powertrain / Engine and ECT / Utility / Secondary Air Injection Check / Manual Mode / AIR PUMP 1: ON, ASV 1: OPEN, AIR PUMP 2: ON, 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, AIR PUMP and ASV operation can be selected.

(n) Start the engine.

(o) Perform the AIR system forced operation while the engine is idling.

(p) Measure the voltage between the SIP and E or SIP2 and E2 terminals of the ECM connector when the AIR system is ON and OFF.

(q) Turn the ignition switch off.

NOTICE:

• Performing Secondary Air Injection Check repeatedly may cause damage to the secondary air injection system. If it is necessary to repeat the check, leave an interval of several minutes between System Check operations to prevent the system from overheating.
• When performing the Secondary Air Injection Check operation after the battery cable has been reconnected, wait for 7 minutes with the ignition switch ON or the engine running.
• Turn the ignition switch off when the Secondary Air Injection Check operation finishes.

Standard Voltage:

NG

REPLACE ECM

OK

(a) Replace the air injection control driver (for bank 1 or bank 2) (See page ).

NEXT

(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 to ON.

(e) Turn the Techstream on.

(f) Clear DTCs (if set) (See page ).

(g) Enter the following menus: Powertrain / Engine and ECT / Utility / Secondary Air Injection Check / Automatic Mode.

(h) Start the engine after the Techstream initialization is finished.

(i) Perform the System Check operation by pressing ENTER (Next).

(j) After operating the AIR system, perform the following to confirm the AIR system pending codes: Press the Exit button.

(k) Check pending DTCs.

(l) Turn the ignition switch off.

OK:

No pending DTC output.

NOTICE:

• When performing the Secondary Air Injection Check operation after the battery cable has been reconnected, wait for 7 minutes with the ignition switch turned to ON or the engine running.
• Turn the ignition switch off when the Secondary Air Injection Check operation finishes.

OK

END

NG

REPLACE ECM

OK:

No blockage and no deformation in vacuum hose.

NG

REPAIR OR REPLACE VACUUM HOSE

OK

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Air pump pressure (Absolute) and Air Pump2 Pressure (Absolute).

(e) Check the pressure displayed on the Techstream.

Standard pressure:

45 to 135 kPa

HINT:

The Techstream displays the air pump pressure as absolute pressure.

A

CHECK FOR INTERMITTENT PROBLEMS

B

REPLACE AIR SWITCHING VALVE ASSEMBLY (FOR BANK 1)

C

REPLACE AIR SWITCHING VALVE ASSEMBLY (FOR BANK 2)