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

A01389UE02

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT ST RELAY

    A0137ZWE02

    1. Remove the ST relay from the engine room R/B.

    2. Check the ST relay resistance.

      Standard Resistance
      Tester Connections Specified Conditions
      3 - 5 10 kΩ or higher
      3 - 5

      Below 1 Ω

      When battery voltage applied to terminals 1 and 2

    3. Reinstall the ST relay.


    NG

    REPLACE ST RELAY

    OK

  2. READ VALUE USING INTELLIGENT TESTER


    1. Connect an intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester ON.

    3. Select the following menu items: Powertrain / Multi-Mode M/T / Data List / STA Switch Signal

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

      Items

      [Abbreviation]

      		 Measurement Items: Display Normal Conditions Diagnostic Notes

      STA Switch Signal

      [STA SW Sig]

      STA signal:

      ON or OFF

      		 ON: During cranking -
      OK
      The STA Switch Signal is ON during cranking.

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

    NG

  3. INSPECT TRANSMISSION CONTROL ECU ASSEMBLY

    A0135VXE01

    1. Turn the ignition switch to ON.

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

    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 Connections Ignition Switch Position Specified Conditions
      STRL (A28-4) - Body ground ON Below 1 V
      STRL (A28-4) - Body ground ST 10 to 14 V

    NG

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

    OK

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


    1. A0136IKE02

      Disconnect the transmission control ECU connector.

    2. A01367XE01

      Remove the ST relay from the engine room R/B.

    3. Check the resistance.

      Standard Resistance
      Tester Connections Specified Conditions
      STRL (A28-4) - STA (A28-6) Below 1 Ω
      STRL (A28-4) - ST relay terminal 1 Below 1 Ω
      STRL (A28-4) - Body ground 10 kΩ or higher
      ST relay terminal 2 - Body ground Below 1 Ω
      ST relay terminal 3 - Starter terminal (B16-1) Below 1 Ω
      ST relay terminal 5 - Body ground 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 CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE