Last Modified: 7-3-2017 6.8:8.0.40 Doc ID: RM000001BRE00AX
Model Year Start: 2007 Model: LX470 Prod Date Range: [08/2006 -           ]
Title: 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1440,P1443; Secondary Air Injection Vacuum Switching Valve Circuit Malfunction Bank 1; 2007 MY LX470 [08/2006 -        ]

DTC

P1440

Secondary Air Injection Vacuum Switching Valve Circuit Malfunction Bank 1

DTC

P1443

Secondary Air Injection Vacuum Switching Valve Circuit Malfunction Bank 2

DESCRIPTION

Refer to DTC P0412 2007 MY LX470 [08/2006 -        ]; 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0412; Secondary Air Injection System Switching Valve "A" Circuit+ .

DTC No.

DTC Detection Condition

Trouble Area

P1440

AIV1 terminal voltage becomes less than half of the +B voltage while the VSV for air injection system is not operating.

(1 trip detection logic)

  • Open or short in VSV for air injection system circuit (bank 1)
  • VSV power source
  • VSV for air injection system (bank 1)
  • ECM

P1443

AIV2 terminal voltage becomes less than half of the +B voltage while the VSV for air injection system is not operating.

(1 trip detection logic)

  • Open or short in VSV for air injection system circuit (bank 2)
  • VSV power source
  • VSV for air injection system (bank 2)
  • ECM

MONITOR DESCRIPTION

The ECM detects an open or short in the circuit of the VSV for air injection system according to the AIV1 (AIV2) terminal voltage, stores the DTC, and then illuminates the MIL. When the AIV1 (AIV2) terminal voltage is less than half of the +B voltage while the VSV for air injection system is not operating, the ECM determines it as a malfunction.

MONITOR STRATEGY

Related DTCs

P1440: Secondary air injection system control valve circuit (bank 1) range check

P1443: Secondary air injection system control valve circuit (bank 2) range check

Required sensors/components

VSV for air injection control

Frequency of operation

Continuous

Duration

0.5 seconds

MIL operation

Immediate

Sequence operation

None

TYPICAL ENABLING CONDITIONS

All:

The monitor will run whenever these DTCs are not present

-

P1440:

Engine

Running

No. 2 air switching valve (bank 1)

Not operating

P1443:

Engine

Running

No. 2 air switching valve (bank 2)

Not operating

TYPICAL MALFUNCTION THRESHOLDS

P1440:

No. 2 air switching valve (bank 1) output terminal level

Low

P1443:

No. 2 air switching valve (bank 2) output terminal level

Low

WIRING DIAGRAM

Refer to DTC P0412 2007 MY LX470 [08/2006 -        ]; 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0412; Secondary Air Injection System Switching Valve "A" Circuit+ .

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 HARNESS AND CONNECTOR (AIR INJECTION SYSTEM POWER SOURCE)

(a) Disconnect the V15 or V16 VSV for air injection system connector.

(b) Turn the ignition switch ON.

(c) Measure the voltage between terminal 1 of the VSV connector and body ground.

Standard:

9 V or more

(d) Reconnect the VSV for air injection system connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

2.

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

(a) Check the harness and connector 2007 MY LX470 [08/2006 -        ]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: ELECTRONIC CIRCUIT INSPECTION PROCEDURE .

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.

CHECK VSV (RESISTANCE)

(a) Disconnect the V15 or V16 VSV for air injection system connector.

(b) Disconnect the 2 vacuum hoses from the VSV.

(c) Measure the resistance of the VSV terminals.

Standard resistance:

Tester Connection

Specified Condition

1 - 2

33 to 39 Ω at 20°C (68°F)

1 - Body ground

10 kΩ or higher

2 - Body ground

10 kΩ or higher

(d) Reconnect the VSV for air injection system connector.

(e) Reconnect the vacuum hose.

NG

REPLACE VSV

OK

REPLACE ECM