P2444

2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2444: Secondary Air Injection System Pump Stuck On Bank1

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

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.





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 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 sets 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





TYPICAL ENABLING CONDITIONS

All:





Case 1:





Case 2:





Case 3:





TYPICAL MALFUNCTION THRESHOLDS

Condition 1:





Condition 2:





Condition 3:





Condition 4:





Condition 5:





Condition 6:





Condition 7:





Condition 8:





Case 1:





Case 2:





Case 3:





Case 4:





MONITOR RESULT

Refer to Checking Monitor Status Mode 6 Data.

WIRING DIAGRAM









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 sets 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:





Pressure Condition in Secondary Air Injection System Case 2:





Pressure Condition in Secondary Air Injection System Case 3:





Pressure Condition in Secondary Air Injection System Case 4:





Pressure Condition in Secondary Air Injection System Case 5:





Pressure Condition in Secondary Air Injection System Case 6:





Pressure Condition in Secondary Air Injection System Case 7:





Pressure Condition in Secondary Air Injection System Case 8:





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.





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.
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 and turn the Techstream ON.
5. 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.

6. Start the engine.
7. Perform the AIR system intrusive operation while the engine is idling.
8. Check that the air pump (AIR PUMP), ASV and pressure in the AIR system passage (PRESSURE) displayed on the tester indicate the conditions shown in the table below.
Standard:






*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.
9. 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 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 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.

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 and turn the Techstream ON.
(c) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(d) Read DTCs.

Result





If any DTCs other than P0418, P0419, P2444, P2445, P2446 and/or P2447 are output, troubleshoot those DTCs first.
C -- GO TO DTC CHART
B -- GO TO AIR PUMP INSPECTION PROCEDURE
A -- Continue to next step.
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 and turn the Techstream ON.
(e) 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.
(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) status displayed on the Techstream indicate the conditions shown in the table below.
Standard:





HINT: *: Average pumping pressure. The pressure should be 1 kPa or more when the AIR system operates.
(i) 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 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 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.

NG -- CHECK VACUUM HOSES (PRESSURE SENSOR - AIR SWITCHING VALVE)
OK -- Continue to next step.
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 and turn the Techstream ON.
(e) Clear DTCs (if set) DTC Check / Clear.
(f) Enter the following menus: Powertrain / Engine and ECT / Utility / Air Injection Check / Automatic Mode.
(g) Start the engine after the Techstream initialization is finished.
(h) Perform the System Check operation by pressing Next.
(i) After operating the AIR system, perform the following to confirm the AIR system pending codes: Press the Exit button.
(j) Check pending DTCs.
(k) 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





B -- CHECK FOR INTERMITTENT PROBLEMS
A -- Continue to next step.
4. CHECK 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.
NG -- REPAIR OR REPLACE VACUUM HOSE
OK -- Continue to next step.
5. INSPECT 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 and 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 that the pressure displayed on the Techstream fluctuates when applying the pressure to the pressure sensor with the pressure gauge.
OK:
Pressure fluctuates in response to pressure applied with pressure gauge.

Result





HINT: The Techstream displays the air pump pressure as absolute pressure.

C -- REPLACE AIR SWITCHING VALVE
B -- REPLACE AIR SWITCHING VALVE
A -- Continue to next step.
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.
NG -- REPAIR OR REPLACE AIR INJECTION SYSTEM PIPING
OK -- Continue to next step.
7. INSPECT AIR PUMP




(a) Disconnect the D57 or E10 air pump connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






Result





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.

C -- REPLACE AIR PUMP
B -- REPLACE AIR PUMP
A -- Continue to next step.
8. INSPECT AIR INJECTION CONTROL DRIVER (AIR INJECTION CONTROL DRIVER POWER SOURCE CIRCUIT)




(a) Disconnect the D48 and D50 or D52 and D54 AID connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:





(c) Turn the ignition switch to ON.
(d) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE AIR INJECTION CONTROL DRIVER POWER SOURCE CIRCUIT
OK -- Continue to next step.
9. CHECK HARNESS AND CONNECTOR (ECM - AIR INJECTION CONTROL DRIVER)




(a) Disconnect the D74 ECM connector.
(b) Disconnect the D50 or D54 AID connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
10. REPLACE AIR INJECTION CONTROL DRIVER
(a) Replace the air injection control driver Removal.
NEXT -- Continue to next step.
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 or Techstream to the DLC3.
(d) Turn the ignition switch to ON and turn the Techstream ON.
(e) Clear DTCs (if set) DTC Check / Clear.
(f) Enter the following menus: Powertrain / Engine and ECT / Utility / Air injection check / Automatic Mode.
(g) Start the engine after the Techstream initialization is finished.
(h) Perform the System Check operation by pressing Next.
(i) After operating the AIR system, perform the following to confirm the AIR system pending codes: Press the Exit button.
(j) Check pending DTCs.
(k) 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.

NG -- REPLACE ECM
OK -- END