MULTI-MODE MANUAL TRANSAXLE SYSTEM Starter Signal Circuit

DESCRIPTION

The ST relay that energizes the starter motor is operated by the transmission control ECU when the appropriate vehicle conditions are satisfied. If the brake pedal is not depressed or the transmission gear is not in neutral, the engine cannot be cranked. The following is the starter operation chart of the multi-mode manual transmission system.


  1. The ignition switch is turned to ON. It activates the multi-mode manual transmission control ECU. (*1)

  2. The transmission control ECU turns on the shift lock solenoid to release the shift lock while the brake pedal is depressed. (*2)

  3. When the transmission gear is shifted into neutral, the park/neutral position switch located on the transmission housing is turned on. The transmission control ECU determines that the shift lever and transmission gear are in neutral (N position) using the shift lever position sensor and the shift and select stroke sensor. (*3)

  4. The brake pedal is depressed and the ignition switch is turned to the ST position. The start signal from ignition switch is sent to the transmission control ECU via the neutral position switch. (*4)

  5. When above conditions are strictly observed, the transmission control ECU outputs starter relay drive signals from the STRL terminal to start the engine. The STA terminal of the transmission control ECU is used to monitor the STRL terminal output. (*5)

A0136Q0E01

WIRING DIAGRAM

A0136NWE01

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. INSPECT ST RELAY


    1. Inspect the ST relay Click here.


    NG

    REPLACE ST RELAY

    OK

  2. READ VALUE USING INTELLIGENT TESTER (STA SWITCH SIGNAL)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Multi-Mode M/T / Data List / STA Switch Signal

    5. Check the value displayed on the tester when the ignition switch is turned to the ON and ST position.

      Tester Display Measurement Items/Range Normal Condition Diagnostic Note

      STA Switch Signal

      [STA SW Sig]

      STA signal:

      ON or OFF

      		 ON: During cranking -
      OK
      The STA Switch Signal is ON during cranking.
      Result
      Result Proceed to
      NG A
      OK B

    B

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

    A

  3. INSPECT TRANSMISSION CONTROL ECU ASSEMBLY

    A0137QSE07
    Text in Illustration
    *a

    Component with harness connected

    (Transmission Control ECU)

    1. Turn the ignition switch to ON.

    2. Confirm that the transmission gear is in neutral with the shift lever in N.

    3. Depress the brake pedal.

    4. Measure the voltage between the transmission control ECU and the body ground when the ignition switch is turned to the ST position.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A28-4 (STRL) - Body ground Ignition switch ON Below 1 V
      A28-4 (STRL) - Body ground Cranking 10 to 14 V

    NG

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

    OK

  4. CHECK HARNESS AND CONNECTOR (TRANSMISSION CONTROL ECU - BATTERY, BODY GROUND)


    1. Disconnect the A28 transmission control ECU connector.

    2. A01367XE02
      Text in Illustration
      *1 Engine Room Relay Block
      *2 ST Relay Holder

      Remove the ST relay from the engine room relay block.

    3. Check the resistance.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A28-4 (STRL) - A28-6 (STA) Always Below 1 Ω
      A28-4 (STRL) - ST relay terminal 1 Always Below 1 Ω
      A28-4 (STRL) - Body ground Always 10 kΩ or higher
      ST relay terminal 2 - Body ground Always Below 1 Ω
      ST relay terminal 3 - Starter terminal (B16-1) Always Below 1 Ω
      ST relay terminal 5 - Body ground Always 10 kΩ or higher

    4. Reconnect the transmission control ECU connector.

    5. Reinstall the ST relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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