P1444
2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1441: Stuck Open in Secondary Air Injection Vacuum Switching Valve Bank 1
DTC P1441 - Stuck Open in Secondary Air Injection Vacuum Switching Valve Bank 1
DTC P1444 - Stuck Open in Secondary Air Injection Vacuum Switching Valve Bank 2
DTC P2440 - Secondary Air Injection System Switching Valve Stuck Open Bank1
DESCRIPTION
The Secondary Air Injection (AIR) system pumps air to the exhaust port to accelerate the activation of the catalyst. The secondary air injection system consists of the ECM, air pump, Air Switching Valve (ASV) (EASV), No. 2 Air Switching Valve (No. 2 ASV) (ASV1, 2), pressure sensor and Air Injection Control Driver (AID). The Air Switching Valve (ASV) (EASV) is an electromagnetic type and No. 2 Air Switching Valve (No. 2 ASV) (ASV1, 2) is a vacuum type.
The secondary air injection system pumps pressurized air to the exhaust port by the air pump through the ASV and No. 2 ASV. The ASV assists the No. 2 ASV. The No. 2 ASV also controls air supply.
The ECM sends signals to the AID, and then the AID operates the air pump and ASV. The pressure sensor detects pressure and exhaust pulsation in the system when the system operates and when it does not operate, and sends the data to the ECM.
MONITOR DESCRIPTION
The ECM detects pressure change with the pressure sensor to determine malfunctioning parts in the system, and stores the DTCs. The ECM measures pressure and/or exhaust pulsation of the system at 6 points, A to F, when the air injection system is in operation or when not in operation. When the pressure is high, the ECM determines that the pump operates. When exhaust pulsation is detected, the ECM determines that the Air Switching Valve (ASV) is open. The ECM determines malfunction parts based on the measured value, and stores the DTCs.
Points A and B:
ECM detects pressure changes (decrease), and determines that the No. 2 Air Switching Valve (No. 2 ASV) is open.
Points C and F:
ECM detects pressure and exhaust pulsation, and determines the pressure pattern of the system.
Point D:
ECM operates the system, as indicated by the dashed lines, to determine which of the No. 2 ASV is malfunctioning only when pressure changes cannot be detected at point A or B.
Point E:
ECM detects exhaust pulsation to determine the condition of the system.
Pressure condition in Secondary Air Injection System (Point C and F)
Pattern 1:
Pattern 2:
Pattern 3:
Pattern 4:
Judgment and decision of failure mode:
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
P1441, P1444:
P2440:
Case 1:
Case 2:
Case 3:
TYPICAL MALFUNCTION THRESHOLDS
P1441 AIR valve bank 1 open stuck:
P1444 AIR valve bank 2 open stuck:
P1441 and P1444 AIR valve bank 1 and bank 2 open stuck:
P2440 AIR valve open stuck:
P2440 AIR valve bank 1 and bank 2 open stuck:
MONITOR RESULT
Refer to Checking Monitor Status Mode 6 Data.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT: Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
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 ON and turn the tester ON.
(c) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(d) Read DTCs.
Result:
HINT: If any DTCs other than P1441, P1444 or P2440 are output, troubleshoot those DTCs first.
C -- GO TO DTC CHART
B -- CHECK NO. 2 AIR SWITCHING VALVE (OPERATION)
A -- Continue to next step.
2. INSPECT AIR SWITCHING VALVE (OPERATION)
(a) Remove the intake manifold Removal.
(b) Remove the Air Switching Valve (ASV).
(c) Blow air into port A and check that air is not discharged from port B.
OK:
Not discharged
(d) Apply battery positive voltage across the terminals.
(e) Blow air into port A and check that air is discharged from port B.
OK:
Discharged
NG -- REPLACE AIR SWITCHING VALVE
OK -- Continue to next step.
3. CHECK AIR SWITCHING VALVE (VOLTAGE)
(a) Remove the intake manifold Removal.
(b) Disconnect the A47 ASV connector.
(c) Turn the ignition switch ON.
(d) Measure the voltage between terminal 1 of the air switching valve connector and body ground.
Standard voltage:
(e) Reconnect the ASV connector.
NG -- CHECK HARNESS AND CONNECTOR (AIR INJECTION CONTROL DRIVER - AIR SWITCHING VALVE)
OK -- CHECK FOR INTERMITTENT PROBLEMS
4. CHECK HARNESS AND CONNECTOR (AIR INJECTION CONTROL DRIVER - AIR SWITCHING VALVE)
(a) Remove the intake manifold Removal.
(b) Disconnect the A44 air injection driver connector.
(c) Disconnect the A47 air switching valve connector.
(d) Disconnect the battery positive terminal cable.
(e) Measure the resistance between the wire harness side connectors.
Standard resistance:
(f) Reconnect the air injection driver connector.
(g) Reconnect the ASV connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. CHECK AIR INJECTION CONTROL DRIVER (VOLTAGE)
(a) Disconnect the A44 Air Injection Control Driver (AID) connector.
(b) Turn the ignition switch ON.
(c) Measure the voltage between terminal 3 (SIV) of the AID connector and body ground.
Standard voltage:
(d) Reconnect the AID connector.
NG -- CHECK HARNESS AND CONNECTOR (AIR INJECTION CONTROL DRIVER - ECM)
OK -- REPLACE AIR INJECTION CONTROL DRIVER
6. CHECK HARNESS AND CONNECTOR (AIR INJECTION CONTROL DRIVER - ECM)
(a) Disconnect the air injection driver connector.
(b) Disconnect the E8 ECM connector.
(c) Measure the resistance between the wire harness side connectors.
Standard resistance:
(d) Reconnect the air injection driver connector.
(e) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM
7. CHECK NO. 2 AIR SWITCHING VALVE (OPERATION)
(a) Start the engine and warm it up.
(b) Turn the ignition switch OFF.
(c) Connect the Techstream to the DLC3.
(d) Start the engine and turn the tester ON.
(e) Enter the following menus: Powertrain / Engine and ECT / Utility / Air Injection Check / Manual Mode / Operation 5 and 6.
HINT:
Operation 5: AP: ON; EASV: OPEN; ASV1: OPEN; ASV2: CLOSE
Operation 6: AP: ON; EASV: OPEN; ASV1: CLOSE; ASV2: OPEN
NOTICE:
- This test only allows technicians to operate the AIR system for 5 seconds. Furthermore, the test can be performed 4 times a trip. If the test is repeated, intervals of at least 30 seconds are required between tests.
While the AIR system operation using the Techstream is prohibited, the tester displays the prohibition (WAIT or ERROR). If ERROR (AI STATUS NG) is displayed on the tester, stop the engine for 10 minutes and then try again.
- 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.
(f) Read values of the air-fuel ratio on the Techstream.
Result:
HINT:
- When the No. 2 ASV operates normally, the A/F value is 18 or more when the valve is open, and approximately 14.5 when the valve is closed.
- Perform the following procedures only on the bank of which the valve is not closed.
NEXT -- Continue to next step.
8. CHECK VSV (FOR AIR INJECTION SYSTEM)
(a) Turn the ignition switch OFF.
(b) Disconnect the vacuum hose from the VSV for air injection system.
(c) Connect the Techstream to the DLC3.
(d) Start the engine and turn the tester ON.
(e) Enter the following menus: Powertrain / Engine and ECT / Utility / Air Injection Check / Manual Mode / Operation 1.
(f) At this time, check that no negative pressure generates at port A of the VSV.
HINT: Operation 1: AP: OFF; EASV: CLOSE; ASV1: CLOSE; ASV2: CLOSE
NOTICE:
- This test only allows technicians to operate the AIR system for 5 seconds. Furthermore, the test can be performed 4 times a trip. If the test is repeated, intervals of at least 30 seconds are required between tests.
While the AIR system operation using the Techstream is prohibited, the tester displays the prohibition (WAIT or ERROR). If ERROR (AI STATUS NG) is displayed on the tester, stop the engine for 10 minutes and then try again.
- 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 to OFF when the Air Injection Check operation finishes.
OK:
No negative pressure is generated.
(g) Reconnect the vacuum hose.
NG -- CHECK VSV (FOR AIR INJECTION SYSTEM)
OK -- Continue to next step.
9. INSPECT NO. 2 AIR SWITCHING VALVE (OPERATION)
(a) Remove the No. 2 air switching valve.
(b) Blow air into port B and check that air is not discharged from port C.
OK:
Not discharged from port C
(c) Apply vacuum 30 kPa (225 mmHg) to port A, blow air into port B and check that air is discharged from port C.
OK:
Discharged from port C
NG -- REPLACE NO. 2 AIR SWITCHING VALVE
OK -- CHECK FOR INTERMITTENT PROBLEMS
10. CHECK VSV (FOR AIR INJECTION SYSTEM)
(a) Disconnect the 2 vacuum hoses.
(b) Disconnect the VSV for air injection system connector.
(c) Blow air into port B and check that air does not flow from port A.
OK:
Air does not flow from port A
(d) Apply battery positive voltage across the terminals. Then blow air into port B and check that air flows from port A.
OK:
Air flows from port A
NG -- REPLACE VSV
OK -- Continue to next step.
11. CHECK HARNESS AND CONNECTOR (ECM - VSV FOR AIR INJECTION SYSTEM)
(a) Remove the intake manifold Removal.
(b) Disconnect the E4 ECM connector.
(c) Disconnect the V12 and V13 VSV connectors for air injection system control.
(d) Measure the resistance between the VSV connector and ECM.
Standard resistance:
(e) Measure the resistance between the VSV connector and body ground.
Standard resistance:
(f) Reconnect the ECM connector.
(g) Reconnect the VSV connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM