SFI SYSTEM Cranking Holding Function Circuit

DESCRIPTION

The cranking holding control system keeps energizing the starter relay from when the power management control ECU detects the starter signal from the ignition switch until the power management control ECU performs a judgement of "Engine started".

When the power management control ECU detects the STSW signal, the power management control ECU outputs the starter relay drive signal (STAR signal) to the starter relay through the clutch start switch or park/neutral position switch, and then, the engine is cranked. When the power management control ECU receives a stable engine speed signal (NE signal), more specifically, when the NE signal reaches a predetermined value, the power management control ECU stops outputting the STAR signal.

Also, the power management control ECU monitors the starter relay operating conditions based on the STA terminal voltage status.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL)

   
   

   1. Connect an intelligent tester to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the tester on.

   4. Enter the following menus: Powertrain / Engine and ECT / Data List / Starter Signal.

   5. Check the result when the ignition switch is turned ON and the engine starts.

      OK
      Condition Starter Signal Ignition switch ON OFF Engine start ON

      Result

      Result	Proceed to
      Outside standard range (for manual transaxle)	A
      Outside standard range (for CVT)	B
      Within standard range (for manual transaxle)	C
      Within standard range (for CVT)	D

   
   

   B

   INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY Click here

   C

   CHECK HARNESS OR CONNECTOR (CLUTCH START SWITCH ASSEMBLY - ECM - ST RELAY) Click here

   D

   CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH ASSEMBLY - ECM - ST RELAY) Click here

   A

2. INSPECT CLUTCH START SWITCH ASSEMBLY

   

   
   

   1. Disconnect the clutch start switch assembly connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition 1 - 2 ON (pushed) Below 1 Ω 1 - 2 OFF (free) 10 kΩ or higher

   3. Reconnect the clutch start switch assembly connector.

   
   

   NG

   REPLACE CLUTCH START SWITCH ASSEMBLY Click here

   OK

3. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - CLUTCH START SWITCH ASSEMBLY)

   

   Text in Illustration

   *1	Front view of wire harness connector: (to Power Management Control ECU)
   *2	Front view of wire harness connector: (to Clutch Start Switch Assembly)

   
   

   1. Disconnect the power management control ECU connector.

   2. Disconnect the clutch start switch assembly connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition D36-3 (STAR) - A29-2 Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition D36-3 (STAR) or A29-2 - Body ground Always 10 kΩ or higher

   4. Reconnect the power management control ECU connector.

   5. Reconnect the clutch start switch assembly connector.

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

4. CHECK HARNESS AND CONNECTOR (CLUTCH START SWITCH ASSEMBLY - ECM - ST RELAY)

   

   Text in Illustration

   *1	Front view of wire harness connector: (to ST relay)
   *2	Front view of wire harness connector: (to ECM)
   *3	Front view of wire harness connector: (to Clutch Start Switch Assembly)

   
   

   1. Remove the ST relay from the engine room relay block.

   2. Disconnect the ECM connector.

   3. Disconnect the clutch start switch assembly connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition ST relay terminal 2 - A18-48 (STA) Always Below 1 Ω ST relay terminal 2 - A29-1 Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition A18-48 (STA) or A29-1 - Body ground Always 10 kΩ or higher

   5. Reinstall the ST relay connector.

   6. Reconnect the ECM connector.

   7. Reconnect the clutch start switch assembly connector.

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

   CHECK ENTRY AND START SYSTEM Click here

5. INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY

   

   Text in Illustration

   *1	Component without harness connected: (Park/Neutral Position Switch)

   
   

   1. Disconnect the park/neutral position switch connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition 4 - 5 Shift position P, N Below 1 Ω 4 - 5 Shift position not P, N 10 kΩ or higher

   3. Reconnect the park/neutral position switch connector.

   
   

   NG

   REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY Click here

   OK

6. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - PARK/NEUTRAL POSITION SWITCH)

   

   Text in Illustration

   *1	Front view of wire harness connector: (to Power Management Control ECU)
   *2	Front view of wire harness connector: (to Park/Neutral Position Switch)

   
   

   1. Disconnect the power management control ECU connector.

   2. Disconnect the park/neutral position switch connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition D36-3 (STAR) - B13-4 Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition D36-3 (STAR) or B13-4 - Body ground Always 10 kΩ or higher

   4. Reconnect the power management control ECU connector.

   5. Reconnect the park/neutral position switch connector.

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

7. CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH ASSEMBLY - ECM - ST RELAY)

   

   Text in Illustration

   *1	Front view of wire harness connector: (to ST relay)
   *2	Front view of wire harness connector: (to ECM)
   *3	Front view of wire harness connector: (to Park/Neutral Position Switch)

   
   

   1. Remove the ST relay from the engine room relay block.

   2. Disconnect the ECM connector.

   3. Disconnect the park/neutral position switch connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition ST relay terminal 2 - A18-48 (STA) Always Below 1 Ω ST relay terminal 2 - B13-5 Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition A18-48 (STA) or B13-5 - Body ground Always 10 kΩ or higher

   5. Install the ST relay.

   6. Reconnect the ECM connector.

   7. Reconnect the park/neutral position switch connector.

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

   CHECK ENTRY AND START SYSTEM Click here

8. CHECK HARNESS OR CONNECTOR (CLUTCH START SWITCH ASSEMBLY - ECM - ST RELAY)

   

   Text in Illustration

   *1	Front view of wire harness connector: (to ST relay)
   *2	Front view of wire harness connector: (to ECM)
   *3	Front view of wire harness connector: (to Clutch Start Switch Assembly)

   
   

   1. Remove the ST relay from the engine room relay block.

   2. Disconnect the ECM connector.

   3. Disconnect the clutch start switch assembly connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition ST relay terminal 2 - A18-48 (STA) Always Below 1 Ω ST relay terminal 2 - A29-1 Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition A18-48 (STA) or A29-1 - Body ground Always 10 kΩ or higher

   5. Reinstall the ST relay.

   6. Reconnect the clutch start switch assembly connector.

   7. Reconnect the ECM connector.

   
   

   B

   INSPECT BATTERY Click here

   A

   REPAIR OR REPLACE HARNESS OR CONNECTOR

9. CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH ASSEMBLY - ECM - ST RELAY)

   

   Text in Illustration

   *1	Front view of wire harness connector: (to ST Relay)
   *2	Front view of wire harness connector: (to ECM)
   *3	Front view of wire harness connector: (to Park/Neutral Position Switch Assembly)

   
   

   1. Remove the ST relay from the engine room relay block.

   2. Disconnect the ECM connector.

   3. Disconnect the park/neutral position switch assembly connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition ST relay terminal 2 - A18-48 (STA) Always Below 1 Ω ST relay terminal 2 - B13-5 Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition A18-48 (STA) or B13-5 - Body ground Always 10 kΩ or higher

   5. Install the ST relay.

   6. Reconnect the ECM connector.

   7. Reconnect the park/neutral position connector.

   
   

   NG

   REPAIR OR REPLACE HARNESS AND CONNECTOR

   OK

10. INSPECT BATTERY

    
    

    1. Check that the battery is not depleted.

       OK
       Battery is not depleted.

    
    

    NG

    REPLACE BATTERY

    OK

11. CHECK BATTERY TERMINAL

    
    

    1. Check that the battery terminals are not loose or corroded.

       OK
       Battery terminals are not loose or corroded.

    
    

    NG

    REPAIR OR REPLACE BATTERY TERMINAL

    OK

    REPAIR OR REPLACE STARTER CIRCUIT (STARTER - ST RELAY)