Lexus IS250 · Service Manual ENGINE

P0660

Diagnostic trouble codes

DESCRIPTION

When the Intake Air Control Valve (IACV) opens and closes, the ACIS control circuit causes the engine load intake efficiency to increase. When the engine is running at 2,450 to 4,100 rpm and the throttle valve opening angle is 30°or more, current flows through the ACIS control circuit and the IACV closes. For all other situations, current does not flow through the ECM and the IACV is open.
A096670E02
DTC No.
 DTC Detection Condition
 Trouble Area
P0660
 The following conditions are met simultaneously for 0.5 seconds or more (2 trip detection logic):
  1. Voltage of terminal ACIS of the ECM is low when the VSV is OFF.
  2. The engine has been started.
  1. Open or short in intake control valve circuit
  2. Surge tank (intake air control valve)
  3. ECM

WIRING DIAGRAM

A122752E01

INSPECTION PROCEDURE


1. PERFORM ACTIVE TEST BY INTELLIGENT TESTER (OPERATE INTAKE AIR CONTROL VALVE)

  1. Connect the intelligent tester to the DLC3.

  1. Start the engine and turn the tester II ON.

  1. Enter the following menus: Power train / Engine / Active Test / Activate the VSV for Intake Control.

  1. Check if operating noise can be heard when operating the intake control valve using the intelligent tester.

    OK:
    Operating noise can be heard.



 OK
CHECK FOR INTERMITTENT PROBLEMS
NG


2. CHECK INTAKE AIR CONTROL VALVE ASSEMBLY (OPERATION)

  1. A093008E06
    Disconnect the E50 intake air control valve connector.

  1. Apply battery voltage between the terminals of the intake air control valve connector.

  1. Check intake air control valve operation.

    OK:
    Operating noise can be heard.



 NG
REPLACE INTAKE AIR SURGE TANK ASSEMBLY
OK


3. CHECK HARNESS AND CONNECTOR (INTAKE AIR CONTROL VALVE - ECM, EFI NO. 2 FUSE)

  1. A110579E05
    Check the wire harness between the intake air control valve connector and the ECM connector.

    1. Disconnect the E50 intake air control valve connector.

    2. Disconnect the E5 ECM connector.

    3. Measure the resistance of the harness side connectors.

      Standard resistance (Check for open):
      Tester Connection
      		 Specified Condition
      E50-1 - ACIS (E5-3)
      		 Below 1 Ω

      Standard resistance (Check for short):
      Tester Connection
      		 Specified Condition
      E50-1 or ACIS (E5-3) - Body ground
      		 10 kΩ or higher

  1. Check the wire harness between the intake air control valve connector and the EFI NO. 2 fuse.

    1. Disconnect the intake air control valve connector.

    2. Remove the EFI NO. 2 fuse from the engine room No. 2 junction block.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance (Check for open):
      Tester Connection
      		 Specified Condition
      E50-2 - EFI NO. 2 fuse (2) of Engine room No. 2 relay block
      		 Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM


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