- Short in air pump circuit
- Open or short in pressure sensor circuit
- Pressure sensor
- 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: RM0000013HD00HX |
| Title: 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia) | ||
|
DTC |
P2444 |
Secondary Air Injection System Pump Stuck On Bank1 |
|
DTC |
P2445 |
Secondary Air Injection System Pump Stuck Off Bank1 |
|
DTC |
P2446 |
Secondary Air Injection System Pump Stuck On Bank 2 |
|
DTC |
P2447 |
Secondary Air Injection System Pump Stuck Off Bank 2 |
DESCRIPTION
Refer to P2440
.
|
DTC No. |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
P2444 P2446 |
Secondary air pressure more than 2.4 kPa (18 mmHg) despite ECM commanding air pump to turn off (2 trip detection logic) |
|
|
P2445 P2447 |
Secondary air pressure less than 2.4 kPa (18 mmHg) despite ECM commanding air pump to turn on (2 trip detection logic) |
|
MONITOR DESCRIPTION
The ECM monitors the pressure in the secondary air passage using the pressure sensor located on the Air Switching Valve (ASV) of the Secondary Air Injection (AIR) system. The sensor measures the pressure in the secondary air passage and transmits a signal to the ECM.
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:
- The pressure indicated by the pressure sensor does not reach threshold levels despite the ECM turning on the air pump.
- The pressure indicated by the pressure sensor exceeds threshold levels despite the ECM turning off the air pump.
MONITOR STRATEGY
|
Related DTCs |
P2444: Air pump stuck ON P2445: Air pump stuck OFF P2446: Air pump stuck ON P2447: Air pump stuck OFF |
|
Required Sensors/Components (Main) |
Pressure sensor |
|
Required Sensors/Components (Related) |
- |
|
Frequency of Operation |
Once per drive cycle |
|
Duration |
Case 3: 1.5 seconds Case 1, 2: 7 seconds |
|
MIL Operation |
2 driving cycles |
|
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 - P2125: TP sensor P0125: Insufficient ECT for Closed Loop P0171 - P0175: Fuel trim P0300 - P0308: Misfire P0325 - 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 P2430 - P2433: AIR Pressure Sensor (Low/High) |
|
Battery voltage |
11 V or more |
|
Atmospheric pressure |
45 kPa (337.5 mmHg) or more |
Case 1
|
Secondary air injection pump |
ON |
|
Secondary air injection switching valve |
ON |
|
Engine speed |
Less than 3750 rpm |
|
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
|
Coolant temperature at engine start |
Less than 5°C (41°F) |
|
Ambient temperature at engine start |
-15°C (5°F) or more |
|
Cumulative intake air amount |
100 g/sec. or more |
|
Secondary air injection system monitor during secondary air injection ON |
Completed |
|
Engine speed |
3000 rpm or more |
|
Throttle angle |
20° or more |
|
AIR valve |
OFF |
|
Pressure sensor malfunction |
Not detected |
|
Air injection driver malfunction |
Not detected |
|
Duration of the following condition |
5 to 60 minutes |
|
Engine coolant temperature |
25°C (77°F) or more |
TYPICAL MALFUNCTION THRESHOLDS
Condition 1
|
AIR pressure during AIR ON |
2.4 kPa or more and pulse is generated |
Condition 2
|
AIR pressure during AIR ON |
Less than 2.4 kPa and pulse is generated |
Condition 3
|
AIR pressure during AIR ON |
2.4 kPa or more and pulse is not generated |
Condition 4
|
AIR pressure during AIR ON |
Less than 2.4 kPa and pulse is not generated |
Condition 5
|
AIR pressure during AIR OFF |
2.4 kPa or more and pulse is generated |
Condition 6
|
AIR pressure during AIR OFF |
Less than 2.4 kPa and pulse is generated |
Condition 7
|
AIR pressure during AIR OFF |
2.4 kPa or more and pulse is not generated |
Condition 8
|
AIR pressure during AIR OFF |
Less than 2.4 kPa and pulse is not generated |
Criteria A
|
Both of following conditions met: |
(a) and (b) |
|
(a) Not condition 6 |
Met |
|
(b) Not condition 8 |
Met |
Criteria B
|
Both of following conditions met: |
(a) and (b) |
|
(a) Not condition 1 |
Met |
|
(b) Not condition 3 |
Met |
Criteria C
|
AIR amount |
140 L/min or less |
Criteria D
|
AIR pressure change |
5 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 |
2.4 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 2.4 kPa |
|
Pulsation Detection |
Exhaust gas pulsation detected |
Pressure Condition in Secondary Air Injection System Case 3
|
Air Pump |
ON |
|
Air Switching Valve |
Closed |
|
Pressure |
2.4 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 2.4 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 |
2.4 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 2.4 kPa |
|
Pulsation Detection |
Exhaust gas pulsation detected |
Pressure Condition in Secondary Air Injection System Case 7
|
Air Pump |
ON |
|
Air Switching Valve |
Closed |
|
Pressure |
2.4 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 2.4 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 2.4 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 DTC P2444, P2445, P2446 AND/OR P2447) |
(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.
Result
|
Result |
Proceed to |
|---|---|
|
P2444, P2445, P2446 and/or P2447 are output |
A |
|
P2444, P2445, P2446 and/or P2447 and P0418 and/or P0419 are output |
B |
|
P2444, P2445, P2446 and/or P2447 and other DTCs (except P0418 and P0419) are output |
C |
If any DTCs other than P0418, P0419, P2444, P2445, P2446 and/or P2447 are output, troubleshoot those DTCs first.
|
|
2. |
PERFORM ACTIVE TEST USING TECHSTREAM (SECONDARY AIR INJECTION SYSTEM OPERATION) |
(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) Enter the following menus: Powertrain / Engine and ECT / 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.
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.
(g) Start the engine.
(h) Perform the AIR system intrusive operation while the engine is idling.
(i) Check that the air pump (AIR PUMP), ASV and pressure in the AIR system passage (PRESSURE) status displayed on the Techstream indicate the conditions shown in the table below.
Standard:
|
Tester Operation |
AIR PUMP |
ASV |
PRESSURE* |
|---|---|---|---|
|
AIR PUMP: ON, ASV: OPEN |
ON |
ON |
2.4 kPa or more |
|
AIR PUMP: OFF, ASV: CLOSE |
OFF |
OFF |
Less than 2.4 kPa |
*: Average pumping pressure. The pressure should be 1 kPa or more when the AIR system operates.
(j) 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.
|
|
3. |
CHECK WHETHER DTC OUTPUT RECURS (DTC P2444, P2445, P2446 AND/OR P2247) |
(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 and ECT / Utility / 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.
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.
Result
|
Result |
Proceed to |
|---|---|
|
P2444, P2445, P2446 and/or P2447 are output |
A |
|
No pending DTC is output |
B |
|
|
4. |
INSPECT VACUUM HOSES (PRESSURE SENSOR - AIR SWITCHING VALVE) |
(a) Check the vacuum hose connections with the pressure sensor and ASV.
(b) Inspect the vacuum hose for blockages and damage.
OK:
Vacuum hose has no blockages or damage.
|
|
5. |
INSPECT AIR SWITCHING VALVE (PRESSURE SENSOR)
|
|
|
6. |
CHECK AIR INJECTION SYSTEM PIPE CONNECTIONS |
(a) Check that all the pipes and hoses between the air pump and ASV are securely connected.
(b) Inspect the pipes and hoses for blockages and damage.
OK:
AIR system piping has no blockages or damage.
|
|
7. |
INSPECT AIR PUMP |
(a) Disconnect the air pump connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1 - 2 |
20°C (68°F) |
0.44 to 1 Ω |
If the result is not as specified, replace the air pump.
HINT:
To check the air pump operation, use the Air Injection Check function described in the System Check.
|
|
8. |
INSPECT AIR INJECTION CONTROL DRIVER (AIR INJECTION CONTROL DRIVER POWER SOURCE CIRCUIT) |
(a) Disconnect the AID connectors.
(b) 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 |
(c) Turn the ignition switch to ON.
(d) 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 |
Always |
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 |
Always |
11 to 14 V (near battery voltage) |
|
D34-5 (+B2) - Body ground |
Ignition switch ON |
11 to 14 V (near battery voltage) |
|
|
9. |
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 |
|---|---|---|
|
D56-54 (AIRP) - D32-4 (SIP) |
Always |
Below 1 Ω |
|
D56-53 (ARP2) - D34-4 (SIP2) |
Always |
Below 1 Ω |
|
|
10. |
REPLACE AIR INJECTION CONTROL DRIVER |
(a) Replace the air injection control driver
.
|
|
11. |
CHECK WHETHER DTC OUTPUT RECURS (DTC P2444, P2445, P2446 AND/OR P2447) |
(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 and ECT / Utility / 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 is 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.
|
|
|