- ASV
- Open or short in ASV circuit
- Pressure sensor
- Pressure sensor circuit
- Air Injection Control Driver (AID)
- ECM
| Last Modified: 11-29-2007 | 1.6 C | |
| Service Category: Engine/Hybrid System | Section: Engine Control | |
| Model Year: 2008 | Model: Sequoia | Doc ID: RM0000013HC00IX |
| Title: 2UZ-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia) | ||
|
DTC |
P2440 |
Secondary Air Injection System Switching Valve Stuck Open Bank1 |
|
DTC |
P2441 |
Secondary Air Injection System Switching Valve Stuck Close Bank1 |
|
DTC |
P2442 |
Secondary Air Injection System Switching Valve Stuck Open Bank 2 |
|
DTC |
P2443 |
Secondary Air Injection System Switching Valve Stuck Closed Bank 2 |
DESCRIPTION
Refer to DTC P0412
.
|
DTC No. |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
P2440 P2442 |
Pressure sensor detects pulsation of exhaust gas despite ECM commanding Air Switching Valve (ASV) to close, while engine running (1 trip detection logic) |
|
|
P2441 P2443 |
Pressure sensor detects no pulsation of exhaust gas despite ECM commanding Air Switching Valve (ASV) to open, while engine running (2 trip detection logic) |
|
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
|
Related DTCs |
P2440: Air control valve stuck open P2441: Air control valve stuck closed P2442: Air control valve stuck open P2443: Air control valve stuck closed |
|
Required Sensors/Components (Main) |
Pressure sensor |
|
Required Sensors/Components (Related) |
- |
|
Frequency of Operation |
Once per drive cycle |
|
Duration |
2 seconds: Case 3 7 seconds: Case 1, 2 |
|
MIL Operation |
1 driving cycle: Case 3 2 driving cycles: Case 1, 2 |
|
Sequence of Operation |
None |
TYPICAL ENABLING CONDITIONS
All
|
Monitor runs whenever following DTCs not present |
P0010 - P0022: VVT System P0031 - P0052: Front A/F Sensor Heater P0102 - P0103: MAF sensor P0110 - P0113: IAT sensor P0115 - P0118: ECT sensor P0120 - P2135: TP sensor P0125: Insufficient ECT for Closed Loop P0171 - P0175: Fuel trim P0300 - P0308: Misfire P0327 - P0333: Knock sensor P0335: CKP sensor P0340 - P0346: VVT sensor P0351 - P0358: Igniter P0441 - P2420: EVAP system P0500: VSS P1340: CMP sensor P2195 - P2A03: A/F sensor P2431 - P2438: AIR Pressure Sensor (Low/High) |
|
Battery voltage |
11 V or more |
|
Atmospheric pressure |
45 kPa (337.5 mmHg) or more |
Case 1
|
Time after secondary injection operation begins |
5 seconds or more |
|
Secondary air injection pump |
ON |
|
Secondary air injection switching valve |
ON |
|
Delay time after engine started |
5 seconds or more |
|
Pressure sensor malfunction |
Not detected |
Case 2
|
Secondary air injection pump |
OFF |
|
Engine speed |
Less than 3000 rpm |
|
Secondary air injection system monitor during secondary air injection ON |
Completed |
|
Pressure sensor malfunction |
Not detected |
Case 3
|
Cumulative intake air amount |
150 g/sec. or more |
|
AIR pump |
OFF |
|
AIR valve |
OFF |
|
AIR status |
OFF |
|
Pressure sensor malfunction |
Not detected |
TYPICAL MALFUNCTION THRESHOLDS
Condition 1
|
AIR pressure during AIR ON |
1 kPa or more and pulse is generated |
Condition 2
|
AIR pressure during AIR ON |
Less than 1 kPa and pulse is generated |
Condition 3
|
AIR pressure during AIR ON |
1 kPa or more and pulse is not generated |
Condition 4
|
AIR pressure during AIR ON |
Less than 1 kPa and pulse is not generated |
Condition 5
|
AIR pressure during AIR OFF |
5 kPa or more and pulse is generated |
Condition 6
|
AIR pressure during AIR OFF |
Less than 5 kPa and pulse is generated |
Condition 7
|
AIR pressure during AIR OFF |
5 kPa or more and pulse is not generated |
Condition 8
|
AIR pressure during AIR OFF |
Less than 5 kPa and pulse is not generated |
Case 1
|
Any of following conditions met: |
(a), (b) or (c) |
|
(a) Conditions 1 and 6 |
Met |
|
(b) Conditions 1 and 5 |
Met |
|
(c) Conditions 2 and 6 |
Met |
Case 2
|
Any of following conditions met: |
(a), (b) or (c) |
|
(a) Conditions 3 and 7 |
Met |
|
(b) Conditions 3 and 8 |
Met |
|
(c) Conditions 4 and 8 |
Met |
Case 3
|
Cumulative pressure pulsation |
100 kPa or more |
MONITOR RESULT
Refer to Checking Monitor Status
.
WIRING DIAGRAM
Refer to DTC P0412
.
INSPECTION PROCEDURE
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 cold engine starts, 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.
Pressure Condition in Secondary Air Injection System Case 1
|
Air Pump |
ON |
|
Air Switching Valve |
Open |
|
Pressure |
1 kPa or more |
|
Pulsation Detection |
Exhaust gas pulsation detected |
Pressure Condition in Secondary Air Injection System Case 2
|
Air Pump |
OFF |
|
Air Switching Valve |
Open |
|
Pressure |
Less than 1 kPa |
|
Pulsation Detection |
Exhaust gas pulsation detected |
Pressure Condition in Secondary Air Injection System Case 3
|
Air Pump |
ON |
|
Air Switching Valve |
Closed |
|
Pressure |
1 kPa or more |
|
Pulsation Detection |
Exhaust gas pulsation not detected |
Pressure Condition in Secondary Air Injection System Case 4
|
Air Pump |
OFF |
|
Air Switching Valve |
Close |
|
Pressure |
Less than 1 kPa |
|
Pulsation Detection |
Exhaust gas pulsation not detected |
Pressure Condition in Secondary Air Injection System Case 5
|
Air Pump |
ON |
|
Air Switching Valve |
Open |
|
Pressure |
5 kPa or more |
|
Pulsation Detection |
Exhaust gas pulsation detected |
Pressure Condition in Secondary Air Injection System Case 6
|
Air Pump |
OFF |
|
Air Switching Valve |
Open |
|
Pressure |
Less than 5 kPa |
|
Pulsation Detection |
Exhaust gas pulsation detected |
Pressure Condition in Secondary Air Injection System Case 7
|
Air Pump |
ON |
|
Air Switching Valve |
Closed |
|
Pressure |
5 kPa or more |
|
Pulsation Detection |
Exhaust gas pulsation not detected |
Pressure Condition in Secondary Air Injection System Case 8
|
Air Pump |
OFF |
|
Air Switching Valve |
Close |
|
Pressure |
Less than 5 kPa |
|
Pulsation Detection |
Exhaust gas pulsation not detected |
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 20 to 30 kPa).
- In case 1, the average pressure is approximately 3 to 11 kPa. The value of 1 kPa indicated in the table above is a threshold for detecting pump malfunctions.
|
Detected Condition while AIR Operating: Air Pump ON, ASV Open |
Detected Condition while AIR not Operating: Air Pump OFF, ASV Closed |
ECM Determination |
DTC Output |
|---|---|---|---|
|
Case 1 |
Case 8 |
Normal |
- |
|
Case 1 |
Case 6 |
ASV stuck open |
P2440 or P2442 |
|
Case 1 |
Case 7 |
Air pump stuck ON |
P2444 or P2446 |
|
Case 2 |
Case 8 |
Air pump stuck OFF |
P2445 or P2447 |
|
Case 3 |
Case 8 |
ASV stuck closed |
P2441 or P2443 |
|
Case 1 |
Case 5 |
ASV stuck open and air pump stuck ON |
P2440 and P2444 or P2442 and P2446 |
|
Case 2 |
Case 6 |
ASV stuck open and air pump stuck OFF |
P2440 and P2445 or P2442 and P2447 |
|
Case 3 |
Case 7 |
ASV stuck closed and air pump stuck ON |
P2441 and P2444 or P2443 and P2446 |
|
Case 4 |
Case 8 |
ASV stuck closed and air pump stuck OFF |
P2441 and P2445 or P2443 and P2447 |
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.
PROCEDURE
|
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 to ON.
(c) Turn the Techstream ON.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read DTCs.
Result
|
Result |
Proceed to |
|---|---|
|
P2440, P2441, P2442 and/or P2443 are output |
A |
|
P2440, P2441, P2442 and/or P2443 and P0412 and/or P0415 are output |
B |
|
P2440, P2441, P2442 and/or P2443 and other DTCs (except P0412 and P0415) are output |
C |
If any DTCs other than P0412, P0415, P2440, P2441, P2442 and/or P2443 are output, troubleshoot those DTCs first.
|
|
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 and No. 2 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 / Utility / 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 intrusive 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 / Utility / 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 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 to ON or the engine running.
- Turn the ignition switch off when the Air Injection Check operation finishes.
OK:
|
Air Pump Operation |
ASV Operation |
Exhaust Gas Pulsation |
|---|---|---|
|
ON |
OFF |
Not detected |
|
ON |
ON |
Detected |
(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 / Utility / 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 intrusive 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.
Standard:
|
AIR System Operation |
Pulsation Condition (ECM Calculation) |
Air-Fuel Ratio (Reference) |
|---|---|---|
|
AIR PUMP: ON, ASV: OPEN |
15 kPa or more |
18 or more |
|
AIR PUMP: OFF, ASV: CLOSE |
Less than 30 kPa |
Approximately 14.5 (around stoichiometric air-fuel ratio) |
Reference:
If the air pump operation is confirmed as normal
, the air-fuel ratio detected in front of three-way catalytic converter changes in response to the secondary air pumped into the exhaust port when the air pump operates.
Result
|
Result |
Proceed to |
|---|---|
|
Outside standard range |
A |
|
Within standard range |
B |
|
|
3. |
INSPECT AIR TUBE (BLOCKAGE AND LEAK) |
(a) Check that the No. 2 and No. 3 air tubes are securely connected to both the exhaust manifold and the ASV.
(b) Inspect the air tube for blockages and damage.
OK:
No blockages and damage on intake pipe.
Result
|
Result |
Proceed to |
|---|---|
|
Within standard range |
A |
|
Outside standard range (for Bank 1) |
B |
|
Outside standard range (for Bank 2) |
C |
|
|
4. |
INSPECT AIR SWITCHING VALVE |
(a) Inspect the air switching valve for Bank 1
.
(b) Inspect the air switching valve for Bank 2
.
Result
|
Result |
Proceed to |
|---|---|
|
OK |
A |
|
NG (for Bank 1) |
B |
|
NG (for Bank 2) |
C |
|
|
5. |
INSPECT AIR INJECTION CONTROL DRIVER (POWER SOURCE OF AIR INJECTION CONTROL DRIVER) |
(a) Disconnect the AID connectors.
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Switch Condition |
Specified Condition |
|---|---|---|
|
D31-1 (BATT) - Body ground |
Ignition switch ON |
11 to 14 V (near battery voltage) |
|
D32-5 (+B) - Body ground |
Ignition switch ON |
11 to 14 V (near battery voltage) |
|
D33-1 (BAT2) - Body ground |
Ignition switch ON |
11 to 14 V (near battery voltage) |
|
D34-5 (+B2) - Body ground |
Ignition switch ON |
11 to 14 V (near battery voltage) |
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
D32-1 (E) - Body ground |
Always |
Below 1 Ω |
|
D34-1 (E2) - Body ground |
Always |
Below 1 Ω |
|
|
6. |
CHECK HARNESS AND CONNECTOR (ECM - AIR INJECTION CONTROL DRIVER) |
(a) Disconnect the ECM connector.
(b) Disconnect the AID connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
D56-28 (AIRV) - D32-3 (SIV) |
Always |
Below 1 Ω |
|
A27-43 (ARV2) - D34-3 (SIV2) |
Always |
Below 1 Ω |
|
|
7. |
REPLACE AIR INJECTION CONTROL DRIVER |
(a) Replace the air injection control driver
.
|
|
8. |
CHECK WHETHER DTC OUTPUT RECURS (DTC P2440, P2441, P2442 AND/OR P2443) |
(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)
.
(g) Enter the following menus: Powertrain / Engine / Utility / Air Injection Check / Automatic Mode.
(h) Start the engine after the Techstream initialization is finished.
(i) Perform the System Check operation by pressing 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 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 Air Injection Check operation finishes.
|
|
10. |
INSPECT VACUUM HOSES (AIR SWITCHING VALVE - PRESSURE SENSOR) |
OK:
No blockage and no deformation in vacuum hose.
|
|
11. |
READ VALUE USING TECHSTREAM (AIR SWITCHING VALVE [PRESSURE SENSOR]) |
(a) Connect a pressure gauge to the air pressure sensor as shown in the illustration.
(b) Connect the Techstream to the DLC3.
(c) Turn the ignition switch to ON.
(d) Turn the Techstream ON.
(e) Enter the following menus: Powertrain / Engine / Data List / Air pump pressure (absolute) and Air Pump2 Pressure (Absolute).
(f) Check that the pressure displayed on the Techstream fluctuates when applying pressure to the pressure sensor with the pressure gauge.
OK:
Pressure fluctuates in response to pressure applied with pressure gauge.
HINT:
The Techstream displays the air pump pressure as absolute pressure.
Result
|
Result |
Proceed to |
|---|---|
|
Within standard range |
A |
|
Outside standard range (for Bank 1) |
B |
|
Outside standard range (for Bank 2) |
C |
|
|
|