2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1441,P1444,P2440; Stuck Open in Secondary Air Injection Vacuum Switching Valve Bank 1; 2006 MY LX470 [05/2005

Last Modified: 4-30-2014	6.6 C	Doc ID: RM000001BRF002X
Model Year: 2006	Model: LX470	Prod Date Range: [05/2005 - ]
Title: 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1441,P1444,P2440; Stuck Open in Secondary Air Injection Vacuum Switching Valve Bank 1; 2006 MY LX470 [05/2005 - ]

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

Refer to DTC P0412 .

DTC No.

DTC Detection Condition

Trouble Area

P1441

No. 2 air switching valve (bank 1) stuck open:

The pressure sensor detects exhaust pulsation, when both of No. 2 air switching valve OFF (and air switching valve ON).

(2 trip detection logic)

VSV for air injection system circuit (bank 1)
No. 2 air switching valve (bank 1)
VSV for air injection system (bank 1)
ECM

P1444

No. 2 air switching valve (bank 2) stuck open:

The pressure sensor detects exhaust pulsation, when both of No. 2 air switching valve OFF (and air switching valve ON).

(2 trip detection logic)

VSV for air injection system circuit (bank 2)
No. 2 air switching valve (bank 2)
VSV for air injection system (bank 2)
ECM

P2440

No. 2 air switching valve stuck open:

The pressure sensor detects exhaust pulsation when the system is not operating (both of No. 2 air switching valve OFF, and air switching valve OFF and air pump OFF).

This DTC means air switching valve and "No. 2 air switching valve bank 1 or bank 2" are stuck open.

(1 trip detection logic)

Air switching valve (ASV)
No. 2 air switching valve (Bank 1 and/or 2)
VSV for air injection system (bank 1 and/or 2)
Air injection control driver (AID)
Air injection control driver circuit
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:

Air Pump	ON
Air Switching Valve and No. 2 Air Switching Valve	Open
Pressure	1 kPa or more
Pulsation detection	Exhaust gas pulsation detected

Pattern 2:

Air Pump	OFF
Air Switching Valve and No. 2 Air Switching Valve	Open
Pressure	Less than 5 kPa
Pulsation detection	Exhaust gas pulsation detected

Pattern 3:

Air Pump	ON
Air Switching Valve and No. 2 Air Switching Valve	Closed
Pressure	1 kPa or more
Pulsation detection	Slight pulsation detected

Pattern 4:

Air Pump	OFF
Air Switching Valve and No. 2 Air Switching Valve	Closed
Pressure	Less than 5 kPa
Pulsation detection	Not detected

Judgment and decision of failure mode:

Monitor						Judgment
C	F	A	B	D	E	DTCs that may be set
Pattern 1	Pattern 1	Pressure changed	Pressure changed	-	No pulsation detected	P2444, P1441 and P1444
Pattern 1	Pattern 1	No pressure changed	Pressure changed	-	No pulsation detected	P2444 and "P1441 or P1444"
Pattern 1	Pattern 1	Pressure changed	No pressure changed	Pulsation detected	No pulsation detected	P2444, P1441 and P1444
Pattern 1	Pattern 1	No pressure changed	No pressure changed	Pulsation detected	No pulsation detected	P2444, P1441 and P1444
Pattern 1	Pattern 2	Pressure changed	Pressure changed	-	No pulsation detected	P1441 and P1444
Pattern 1	Pattern 2	No pressure changed	Pressure changed	-	No pulsation detected	P1441 or P1444
Pattern 1	Pattern 2	Pressure changed	No pressure changed	Pulsation detected	No pulsation detected	P1441 and P1444
Pattern 1	Pattern 2	No pressure changed	No pressure changed	Pulsation detected	No pulsation detected	P1441 and P1444
Pattern 1	Pattern 3	Pressure changed	Pressure changed	-	No pulsation detected	P2444
Pattern 1	Pattern 3	No pressure changed	Pressure changed	-	No pulsation detected	P2444 and "P1442 or P1445"
Pattern 1	Pattern 3	Pressure changed	No pressure changed	No pulsation detected	No pulsation detected	P2444 and "P1442 or P1445"
Pattern 1	Pattern 3	No pressure changed	No pressure changed	No pulsation detected	No pulsation detected	P2444, P1442 and P1444
Pattern 1	Pattern 4	Pressure changed	Pressure changed	-	No pulsation detected	Normal
Pattern 1	Pattern 4	Pressure changed	No pressure changed	Pulsation detected	No pulsation detected	Normal
Pattern 1	Pattern 4	Pressure changed	No pressure changed	No pulsation detected	No pulsation detected	P1442 or P1445
Pattern 1	Pattern 4	No pressure changed	Pressure changed	-	No pulsation detected	P1442 or P1445
Pattern 1	Pattern 4	No pressure changed	No pressure changed	Pulsation detected	No pulsation detected	P1442 or P1445
Pattern 1	Pattern 4	No pressure changed	No pressure changed	No pulsation detected	No pulsation detected	P1442 and P1445
Pattern 2	-	No pressure changed	No pressure changed	-	-	P2445
Pattern 3	Pattern 3	No pressure changed	No pressure changed	No pulsation detected	No pulsation detected	P2441, P2444, P1442 and P1445
Pattern 3	Pattern 4	No pressure changed	No pressure changed	No pulsation detected	No pulsation detected	P2441, P1442 and P1445
Pattern 4	-	No pressure changed	No pressure changed	-	-	P2445
-	-	-	-	-	Pulsation detected	P2440 and "P1441 or P1444"

MONITOR STRATEGY

Related DTCs	(Case 1) P1444 AIR VSV stuck open bank 1 (Case 2) P1444 AIR VSV stuck open bank 2 (Case 3) P1441, P1444 AIR VSVs stuck open (Case 4) P2440 AIR valve stuck open (Case 5) P2440 AIR valve and AIR VSVs stuck open
Required sensors/Components	AIR pressure sensor, AIR valve, AIR VSV bank 1, AIR VSV bank 2
Frequency of operation	Once per driving cycle
Duration	Within 60 seconds
MIL operation	2 driving cycles
Sequence operation	None

TYPICAL ENABLING CONDITIONS

Common conditions

This monitor runs whenever these DTCs are not present	P0010 - P0022: VVT system P0031 - P0052: Front A/F sensor heater P0100 - P0103: MAF sensor P0110 - P0113: IAT sensor P0115 - P0118: ECT sensor P0120 - P2125: TP sensor P0125: 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
Atmospheric pressure	45 kPa or higher
Battery voltage	11.5 V or higher

Conditions for Case 1, Case 2 and Case 4

Sequence 1 - 5 are performed to monitor AIR	-
[Sequence 1]	-
Idle	ON
AIR	In operation
AIR pump	ON
AIR valve	ON
AIR VSV bank 1	ON (OFF)
AIR VSV bank 2	OFF (ON)
[Sequence 2]	-
Idle	ON
AIR	In operation
AIR valve	ON
AIR VSV bank 1	ON
AIR VSV bank 2	ON
[Sequence 3]	-
Engine RPM	Less than 3,750 rpm
AIR	In operation
AIR pump	ON
AIR valve	ON
AIR VSV bank 1	ON
AIR VSV bank 2	ON
[Sequence 4-a]	Performed when AIR pressure changes at sequence 2
Engine RPM	Less than 3,750 rpm
AIR	Not operating
AIR pump	OFF
AIR valve	OFF
AIR VSV bank 1	OFF
AIR VSV bank 2	OFF
[Sequence 4-b]	Performed when AIR pressure does not change at sequence 2
Engine RPM	Less than 3,750 rpm
AIR	Not operating
AIR pump	ON
AIR valve	ON
AIR VSV bank 1	ON (OFF)
AIR VSV bank 2	OFF (ON)
[Sequence 5]	-
Engine RPM	Less than 3,750 rpm
AIR	Not operating
AIR pump	OFF
AIR valve	ON
AIR VSV bank 1	OFF
AIR VSV bank 2	OFF

Conditions for Case 3

ECT at engine start	Lower than 5°C (41°F)
IAT at engine start	-15°C (5°F) or higher
Time after engine start	10 seconds or more
Intake air amount	40 g/sec. or more
Engine RPM	Lower than 3,750 rpm
AIR	Not operating
AIR pump	OFF
AIR valve	ON
AIR VSV bank 1	OFF
AIR VSV bank 2	OFF

Conditions for Case 5

Engine RPM	Lower than 3,750 rpm
Cumulative intake air amount	172 g/sec. or more
AIR	Not operating
AIR pump	OFF
AIR valve	OFF
AIR VSV bank 1	OFF
AIR VSV bank 2	OFF

TYPICAL MALFUNCTION THRESHOLDS

Thresholds for Case 1

Averaged AIR pressure at sequence 3	More than 1 kPa
Cumulative AIR pressure pulse at sequence 3	More than 15 kPa
Averaged AIR pressure at sequence 5	Less than 5 kPa
Cumulative AIR pressure pulse at sequence 5	More than 30 kPa

Thresholds for Case 2

Averaged AIR pressure at sequence 3	More than 1 kPa
Cumulative AIR pressure pulse at sequence 3	More than 15 kPa
Averaged AIR pressure at sequence 5	Less than 5 kPa
Cumulative AIR pressure pulse at sequence 5	More than 30 kPa

Thresholds for Case 3

Cumulative AIR pressure pulse

100 kPa or more

Thresholds for Case 4

Averaged AIR pressure at sequence 3	More than 1 kPa
Cumulative AIR pressure pulse at sequence 3	More than 15 kPa
Averaged AIR pressure at sequence 5	More than 5 kPa
Cumulative AIR pressure pulse at sequence 5	Less than 30 kPa

Thresholds for Case 5

Cumulative AIR pressure pulse

100 kPa or more

MONITOR RESULT

Refer to CHECKING MONITOR STATUS .

Monitor ID	Test ID	Scaling	Unit	Description
$71	$E1	Multiply by 0.01	g/sec.	AIR amount for AIR insufficient
$71	$E2	Multiply by 0.01	kPa	Averaged AIR pressure for AIR pump stuck ON
$71	$E3	Multiply by 0.01	kPa	Averaged AIR pressure for AIR pump stuck OFF
$71	$E4	Multiply by 0.01	kPa	AIR pressure pulse for AIR valve and AIR VSV stuck open
$71	$E5	Multiply by 0.01	kPa	AIR pressure pulse for AIR valve and AIR VSV stuck close
$71	$E6	Multiply by 0.01	kPa	AIR pressure difference for AIR valve
$71	$E7	Multiply by 0.01	kPa	AIR pressure difference for AIR VSV bank 1
$71	$E8	Multiply by 0.01	kPa	AIR pressure difference for AIR VSV bank 2
$71	$E9	Multiply by 0.01	kPa	AIR pressure pulse for AIR VSV stuck open bank 1 and bank 2

WIRING DIAGRAM

Refer to DTC P0412 .

INSPECTION PROCEDURE

HINT:

Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.

PROCEDURE

1.	CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO SECONDARY AIR INJECTION SYSTEM DTCS)

(a) Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.

(b) Turn the ignition switch ON and turn the tester ON.

(d) Read DTCs.

Display (DTC Output)	Proceed To
"P1441 and/or P1444" and P2440	A
P1441 and/or P1444	B
"P1441 and/or P1444 and/or P2440" and other DTCs	C

HINT:

If any DTCs other than P1441, P1444 or P2440 are output, troubleshoot those DTCs first.

GO TO STEP 7

GO TO DTC CHART

2.	CHECK AIR SWITCHING VALVE (OPERATION)

(a) Remove the intake manifold .

(b) Remove the Air Switching Valve (ASV).

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

REPLACE AIR SWITCHING VALVE

3.	CHECK AIR SWITCHING VALVE (VOLTAGE)

(a) Remove the intake manifold .

(b) Disconnect the A59 ASV connector.

(d) Measure the voltage between terminal 1 of the air switching valve connector and body ground.

Standard voltage:

Tester Connection	Specified Condition
A59-1 - Body ground	Below 1.0 V

(e) Reconnect the ASV connector.

GO TO STEP 4

CHECK FOR INTERMITTENT PROBLEMS

4.	CHECK HARNESS AND CONNECTOR (AIR INJECTION CONTROL DRIVER - AIR SWITCHING VALVE)

(a) Check harness and connector .

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	CHECK AIR INJECTION CONTROL DRIVER (VOLTAGE)

(a) Disconnect the A56 Air Injection Control Driver (AID) connector.

(b) Turn the ignition switch ON.

Standard voltage:

Tester Connection	Specified Condition
A56-3 (SIV) - Body ground	10 V or more

(d) Reconnect the AID connector.

GO TO STEP 6

REPLACE AIR INJECTION CONTROL DRIVER

6.	CHECK HARNESS AND CONNECTOR (AIR INJECTION CONTROL DRIVER - ECM)

(a) Check harness and connector .

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE ECM

7.	CHECK NO. 2 AIR SWITCHING VALVE (OPERATION)

(a) Start the engine and warm it up.

(b) Turn the ignition switch OFF.

(d) Start the engine and push the the intelligent tester main switch ON.

(e) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / SYSTEM CHECK / AIR INJ CHECK / MANUAL / 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 AI 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 AI system operation using the the intelligent tester 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 INJ 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 INJ CHECK operation finishes.

(f) Read values of the A/F BANK1 and BANK2 on the the intelligent tester.

Air switching valve No. 2 operation	Air fuel ratio
Open	18 or more
Closed	Approximately 14.5

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.

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.

(d) Start the engine and turn the tester ON.

(e) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / SYSTEM CHECK / AIR INJ CHECK / MANUAL / 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 AI 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 AI system operation using the the intelligent tester 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 INJ 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 INJ CHECK operation finishes.

OK:

No negative pressure is generated.

(g) Reconnect the vacuum hose.

GO TO STEP 10

9.	CHECK 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

OK:

Discharged from port C

REPLACE NO. 2 AIR SWITCHING VALVE

CHECK FOR INTERMITTENT PROBLEMS

10.	CHECK VSV (FOR AIR INJECTION SYSTEM)

(a) Disconnect the 2 vacuum hoses.

(b) Disconnect the VSV for air injection sytem connector.

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

REPLACE VSV

11.	CHECK HARNESS AND CONNECTOR (ECM - VSV FOR AIR INJECTION SYSTEM)

(a) Check harness and connector .

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE ECM