STOP AND START SYSTEM STA Signal Circuit

DESCRIPTION

While the engine is being cranked, a starter operation request signal is sent to terminal STA of the ECM.

Tech Tips

If there is an open in the STA circuit of the ECM, stop and start control will be prohibited after the third time the engine is started by stop and start control.


  • Stop and start control will be prohibited until the engine switch is turned off.

  • The MIL will not illuminate.

  • If there is an open in the STA circuit of the ECM, the engine can still be started using the engine switch, as the ECM also receives the starter operation request signal from the engine stop and start ECU via CAN communication. (Stop and start control is prohibited as the reliability of the signal sent via CAN communication cannot be assured while the voltage drops during operation of the starter assembly.)

A01RAYAE01

WIRING DIAGRAM

A01REP7E04

PROCEDURE


  1. READ VALUE USING GTS (STARTER SW)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine / Data List / Starter SW.


      Powertrain > Engine > Data List
      Tester Display
      Starter SW

    5. Read the values displayed on the GTS when the engine switch is on (IG) and on (START).

      OK
      Tester Display Condition Normal Condition
      Starter SW Engine switch on (IG) OFF
      Engine switch on (START) ON
      Result
      Proceed to
      OK
      NG

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

  2. CHECK HARNESS AND CONNECTOR (ECM - ST NO. 2 RELAY)


    1. Disconnect the A66 engine stop and start ECU connector.

    2. Disconnect the A46 ECM connector.

    3. Remove the ST NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A46-29 (STA) - ST NO. 2 relay terminal 2 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR