Last Modified: 4-30-2014 6.6 C Doc ID: RM0000013TK005X
Model Year: 2006 Model: LX470 Prod Date Range: [05/2005 -           ]
Title: 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0418; Secondary Air Injection System Control "A" Circuit; 2006 MY LX470 [05/2005 -        ]

DTC

P0418

Secondary Air Injection System Control "A" Circuit

DESCRIPTION

Refer to DTC P0412 2006 MY LX470 [05/2005 -        ]; 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0412; Secondary Air Injection System Switching Valve "A" Circuit+ .

DTC No.

DTC Detection Condition

Trouble Area

P0418

Both of the following conditions are met, when idling just after cold start (1 trip detection logic):

  1. Air injection (AI) system does not operate
  2. Air injection control driver (AID) outputs air pump malfunction signal (20% duty signal)
  • Open in air pump drive circuit
  • Short between air pump circuit and +B circuit
  • Air pump
  • Air injection control driver (AID)
  • ECM

P0418

Both of the following conditions are met, when idling just after cold start (1 trip detection logic):

  1. Air injection (AI) system operates
  2. Air injection control driver (AID) outputs air pump malfunction signal (20% duty signal)
  • Short between air pump circuit and body ground
  • Air pump
  • AID
  • ECM

MONITOR DESCRIPTION

Air Injection Control Driver (AID) detects an open or short in the air pump and Air Switching Valve (ASV) circuit according to the terminal voltage and sends a signal as diagnostic information to the ECM.

When the air injection system operation is required while the engine is warming up, the ECM transmits command signals to the AID to drive the air pump and ASV.

The AID inputs the command signal from ECM if: 1) VP terminal voltage is low despite the AID inputting the command signal from the ECM to drive the ASV or 2,) VP terminal voltage is high despite the AID not inputting the command signal from the ECM.

The ECM sets the DTC based on the diagnostic information from the AID.

MONITOR STRATEGY

Related DTCs

P0418: Air pump range check

Required sensors/components

Air injection control driver, Air pump

Frequency of operation

Continuous

Duration

3 seconds

MIL operation

Immediate

Sequence operation

None

TYPICAL ENABLING CONDITIONS

All:

The monitor will run whenever this DTC is not present

-

Case 1:

Air pump

Operating

Air switching valve

Operating

Battery voltage

8 V or more

Ignition switch

ON

Starter

OFF

Case 2:

Air pump

Not operating

Air switching valve

Not operating

Battery voltage

8 V or more

Ignition switch

ON

Starter

OFF

TYPICAL MALFUNCTION THRESHOLDS

Case 1, 2:

Diagnostic signal duty ratio from air injection control driver

11 to 29%

COMPONENT OPERATING RANGE

Diagnostic signal duty ratio from air injection control driver

70 to 90% when secondary air injection system operating

and

0% when secondary air injection system not operating

WIRING DIAGRAM

Refer to DTC P0412 2006 MY LX470 [05/2005 -        ]; 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0412; Secondary Air Injection System Switching Valve "A" Circuit+ .

INSPECTION PROCEDURE

HINT:

The diagnostic information output from the AID can be confirmed by connecting an oscilloscope to the diagnostic information terminal of the AID. It narrows the trouble area search to read the waveform on the oscilloscope when performing the AI system intrusive operation function provided in the SYSTEM CHECK.

  • (1) Start the engine and warm it up.
  • (2) Turn the ignition switch OFF.
  • (3) Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
  • (4) Connect an oscilloscope probe to the AIDI terminal of the ECM.
  • (5) Start the engine and turn the tester ON.
  • (6) On the tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / SYSTEM CHECK / AIR INJ SYSTEM.
  • (7) On the tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / SYSTEM CHECK / AIR INJ CHECK / MANUAL / OPERATION 1 and 2.

    HINT:

    OPERATION 1: AP: OFF; EASV: CLOSE; ASV1: CLOSE; ASV2: CLOSE

    OPERATION 2: AP: ON; EASV: OPEN; ASV1: OPEN; ASV2: OPEN

  • (8) Monitor the voltage output of the AID (duty ratio signal).

    Oscilloscope range:

    Items

    Contents

    Terminals

    CH1: AIDI - E1

    Equipment Settings

    5 V/Division, 20 to 40 ms/Division

    Conditions

    Idling

    NOTICE:

    • This AIR INJECTION CHECK only allows technicians to operate the AI system for 5 seconds.

      Furthermore, the check can be performed 4 times a trip. If the test is repeated, intervals of at least 30 seconds are required between checks.

      While the AI system operation using the intelligent tester is prohibited, the tester displays the prohibition (AI STATUS NG) or ERROR. If ERROR (AI STATUS NG) is displayed on the tester,stop the engine for 10 minutes and then try again.

    • Performing the AIR INJ CHECK over and over again may cause damage in the secondary air injection system. If necessary, wait several minutes between tests to prevent overheating the system.
    • 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.

AID Diagnostic Signal Waveform

ECM Command

DTC

(ECM Output)

Suspected Trouble Area

100% Duty Ratio

See waveform 1

Any Air Injection (AI) System operation

P1613
  • Open in diagnostic signal circuit
  • Air Injection Control Driver (AID)
  • Open in AID +B circuit (AID power source)
  • Short between +B circuit and diagnostic signal circuit

0% Duty Ratio

See waveform 2

AI System: ON

(Air pump ON, ASV ON)

P1613
  • Open or short in air pump or Air Switching Valve (ASV) command signal circuit (ECM - AID)
  • Open in AID ground circuit
  • Short between diagnostic signal circuit and body ground
  • AID
  • ECM

AI System: OFF

(Air pump OFF, ASV OFF)

-
  • Normal

20% Duty Ratio

See waveform 3

Air Pump: ON

P0418
  • Short between air pump drive circuit and body ground
  • Harness & connector (AID - Pump)
  • Air Pump
  • AID
  • ECM

Air Pump: OFF

P0418
  • Open in air pump drive circuit (AID - Pump), or short between air pump drive circuit and +B
  • Harness & connector (AID - Pump)
  • Air Pump
  • AID
  • ECM

40% Duty Ratio

See waveform 4

ASV: ON

P0412
  • Short between ASV drive circuit and body ground
  • Harness & connector (AID - ASV)
  • ASV
  • AID
  • ECM

ASV: OFF

P0412
  • Open in ASV drive circuit (AID - ASV), or short between ASV drive circuit and +B
  • Harness & connector (AID - ASV)
  • AID
  • ASV
  • ECM

80% Duty Ratio

See waveform 5

AI System: OFF

(Air pump OFF, ASV OFF)

P1613
  • AID
  • ECM

AI System: ON

(Air pump ON, ASV ON)

-
  • Normal

Excluding Above

(excluding 0, 20, 40, 80, 100% duty)

-

P1613
  • AID
  • Open in AID ground circuit

1. Waveform 1

  • 100% Duty Ratio

2. Waveform 2

  • 0% Duty Ratio

3. Waveform 3

  • 20% Duty Ratio

4. Waveform 4

  • 40% Duty Ratio

5. Waveform 5

  • 80% Duty Ratio

HINT:

  • Using the AIR INJ CHECK operation of the SYSTEM CHECK provided in the intelligent tester function, conditions for air fuel ratio and pressure in the secondary air injection system passage can be checked while the secondary air injection system is operating. It helps technicians to troubleshoot the system when it is malfunctioning.
  • Read freeze frame data using the intelligent tester. Freeze frame data record 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.

PROCEDURE

1.

INSPECT AIR PUMP

(a) Remove the intake manifold 2006 MY LX470 [05/2005 -        ]; 2UZ-FE ENGINE MECHANICAL: CYLINDER HEAD: REMOVAL+ .

(b) Disconnect the A58 air pump connector.

(c) Measure the resistance of the air pump.

Standard resistance:

Tester Connections

Specified Conditions

1 - 2

0.4 to 1.0 Ω

(d) Reconnect the air pump connector.
NG

REPLACE AIR PUMP

OK

2.

CHECK HARNESS AND CONNECTOR (AIR PUMP - BODY GROUND)

(a) Remove the intake manifold 2006 MY LX470 [05/2005 -        ]; 2UZ-FE ENGINE MECHANICAL: CYLINDER HEAD: REMOVAL+ .

(b) Disconnect the A58 air pump connector.

(c) Measure the resistance of the wire harness side connectors and body ground.

Standard resistance:

Tester Connection

Specified Condition

A58-1 - Body ground

Below 1 Ω

(d) Reconnect the air pump connector.
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.

CHECK HARNESS AND CONNECTOR (AIR INJECTION CONTROL DRIVER - AIR PUMP)

(a) Check harness and connector 2006 MY LX470 [05/2005 -        ]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: ELECTRONIC CIRCUIT INSPECTION PROCEDURE .

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

REPLACE AIR INJECTION CONTROL DRIVER