Dtc P1625 Idle Signal Transmitter Circuit

Engine. Lexus Is250, Is220D. Gse20 Ale20
2Ad-Fhv Engine Control System. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK HARNESS AND CONNECTOR (EDU - ECM)

REPLACE EDU

CHECK WHETHER DTC OUTPUT RECURS

DTC P1625 Idle Signal Transmitter Circuit


DESCRIPTION

The ECM reduces injector operation speed and applied voltage to the injector to reduce the sound it produces during idling. To do this, the ECM outputs applied voltage switching signals to terminal IJEN of the EDU from terminal IDLO of the ECM.

DTC No.
DTC Detection Condition
Trouble Area
P1625
  1. With the engine running at idle, voltage of the ECM IDLO terminal is 0.05 V or less for 3 seconds or more.
  2. With the engine running at speeds higher than idle, voltage of the ECM IDLO terminal is 3.4 V or more for 3 seconds or more.
  1. Open or short in idle control circuit
  2. ECM

WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System.
Dtc
  P1625  Idle Signal Transmitter Circuit


INSPECTION PROCEDURE

NOTICE:
After replacing the ECM, the new ECM needs registration (Click here) and initialization (Click here).
1.CHECK HARNESS AND CONNECTOR (EDU - ECM)


    Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System.
Dtc
  P1625  Idle Signal Transmitter Circuit
  1. Disconnect the E85 EDU connector.

  1. Disconnect the E59 ECM connector.

  1. Measure the resistance between the wire harness connector.

    Standard resistance:
    Tester Connection
    Specified Condition
    IDLO (E59-62) - IJEN (E85-2)
    Below 1 Ω
    IDLO (E59-62) or IJEN (E85-2) - Body ground
    10 kΩ or higher
  1. Reconnect the EDU and ECM connectors.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


2.REPLACE EDU

NEXT


3.CHECK WHETHER DTC OUTPUT RECURS
  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch ON (IG) and turn the tester ON.

  1. Clear DTCs.

  1. Start the engine, then idle and race the engine three times at 5-second intervals.

  1. Enter the following menus: Powertrain / Engine / DTC.

    Result:
    Display (DTC Output)
    Proceed to
    P1625
    A
    No output
    B


B
SYSTEM IS OK
A

REPLACE ECM