Home › Engine/Hybrid System › Engine Control › 3UR-FE ENGINE CONTROL: SFI SYSTEM
Last Modified: 11-27-2007 1.6 C
Service Category: Engine/Hybrid System Section: Engine Control
Model Year: 2008 Model: LX570 Doc ID: RM0000012FZ00FX
Title: 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 LX570)

DTC

P0418

Secondary Air Injection System Control "A" Circuit

DTC

P0419

Secondary Air Injection System Control "B" Circuit

DESCRIPTION

Refer to DTC P0412 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 LX570)+ .

DTC Code

DTC Detection Condition

Trouble Area

P0418

P0419

After a cold engine start, all of the following conditions are met (1 trip detection logic):

  • Open in air pump drive circuit
  • Air pump
  • Air injection control driver (AID)
  • ECM

P0418

P0419

After a cold engine start, all of the following conditions are met (1 trip detection logic):

  • Short between air pump drive circuit and body ground
  • Air pump
  • Air injection control driver (AID)
  • ECM

MONITOR DESCRIPTION

The Air Injection Control Driver (AID) detects open and short circuits according to the voltages of the air pump terminal (VP) and the Air Switching Valve (ASV) terminal (VV), and transmits diagnostic information as a signal to the ECM.

For a short time after a cold engine start, the ECM transmits command signals to the AID to drive the air pump and ASV.

The AID transmits an air pump malfunction signal to the ECM if either of the following conditions is met:

  • The voltage at the AID terminal relating to the air pump is low despite the AID receiving command signals from the ECM to drive the air pump.
  • The voltage at the AID terminal relating to the air pump is high despite the AID receiving no command signals from the ECM to drive the air pump.

The ECM stores the DTC based on diagnostic signals from the AID.

MONITOR STRATEGY

Related DTCs

P0418: Secondary air injection system air pump circuit range check (Bank 1)

P0419: Secondary air injection system air pump circuit range check (Bank 2)

Required Sensors/Components (Main)

Air injection control driver

Required Sensors/Components (Related)

Air pump

Frequency of Operation

Once per drive cycle

Duration

3 seconds

MIL Operation

Immediate

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Case 1:

Monitor runs whenever following DTCs not stored

-

Secondary air injection pump

Operating

Secondary air injection switching valve

Operating

Battery voltage

8 V or higher

Engine switch

On (IG)

Starter

OFF

Case 2:

Monitor runs whenever following DTCs not stored

-

Secondary air injection pump

Not operating

Secondary air injection switching valve

Not operating

Battery voltage

8 V or higher

Engine switch

On (IG)

Starter

OFF

TYPICAL MALFUNCTION THRESHOLDS

Diagnostic signal duty ratio from air injection control driver

11% or more, and 29% or less

COMPONENT OPERATING RANGE

Diagnostic signal duty ratio from air injection control driver

70% or more, and 90% or less when secondary air injection system operating.

0% when secondary air injection system not operating.

WIRING DIAGRAM

Refer to DTC P0412 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 LX570)+ .

INSPECTION PROCEDURE

HINT:

Diagnostic information output by the AID can be confirmed by connecting an oscilloscope to the diagnostic information terminal of the AID. Reading the waveform while performing the AIR system intrusive operation provided in the System Check function allows the possible trouble areas to be narrowed down.

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 engine switch turned on (IG) or the engine running.
  • Turn the engine switch off when the Air Injection Check operation finishes.

AID Diagnostic Signal Waveforms

ECM

Commands

DTCs

(ECM Output)

Suspected Trouble Areas

100% Duty Ratio

Any Secondary Air Injection (AIR) System operation

P1613

P1614
  • Open in diagnostic signal circuit
  • Air Injection Control Driver (AID)
  • Open in AID BATT circuit
  • Short between +B and diagnostic signal circuits

0% Duty Ratio

AIR System: ON (Air pump ON, ASV ON)

P1613

P1614
  • Open or short in air pump or Air Switching Valve (ASV) command signal circuit (ECM - AID)
  • Short between diagnostic signal circuit and body ground
  • AID
  • ECM

AIR System: OFF (Air pump OFF, ASV OFF)

-

Normal

20% Duty Ratio

Air Pump: ON

P0418

P0419
  • Short between air pump drive circuit and body ground
  • Harness and connector (AID - Pump)
  • Air pump
  • AID
  • ECM

Air Pump: OFF

P0418

P0419
  • Open in air pump drive circuit (AID - Pump)
  • Harness and connector (AID - Pump)
  • Air pump
  • AID
  • ECM

40% Duty Ratio

ASV: ON

P0412

P0415
  • Short between ASV drive circuit and body ground
  • Harness and connector (AID - ASV)
  • ASV
  • AID
  • ECM

ASV: OFF

P0412

P0415
  • Open in ASV drive circuit (AID - ASV)
  • Harness and connector (AID - ASV)
  • AID
  • ASV
  • ECM

80% Duty Ratio

AIR System: OFF (Air pump OFF, ASV OFF)

P1613

P1614
  • AID
  • ECM

AIR System: ON (Air pump ON, ASV ON)

-

Normal

Other than above

(other than 0, 20, 40, 80 and 100% duty)

-

P1613

P1614
  • AID
  • Open in AID ground circuit

HINT:

  • 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.
  • 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.

PROCEDURE

1.

INSPECT AIR PUMP ASSEMBLY


(a) Disconnect the C33 or C34 air pump connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

1 - 2

20°C (68°F)

0.44 to 1 Ω
OK

2.

CHECK HARNESS AND CONNECTOR (AIR PUMP - BODY GROUND)


(a) Disconnect the C33 or C34 air pump connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

C33-1 - Body ground

Always

Below 1 Ω

C34-1 - Body ground

Always

Below 1 Ω
OK

5.

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


(a) Disconnect the C33 or C34 air pump connector.

(b) Disconnect the C29 or C31 AID connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

C33-2 - C29-2 (VP)

Always

Below 1 Ω

C34-2 - C31-2 (VP2)

Always

Below 1 Ω
OK