SFI SYSTEM > Cranking Holding Function Circuit

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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


A202814E02


INSPECTION PROCEDURE

1.READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL)

  1. Connect an intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

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

  1. 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
Go to step 5

C
Go to step 8

D
Go to step 9
A


2.INSPECT CLUTCH START SWITCH ASSEMBLY
A159771E01

  1. Disconnect the clutch start switch assembly connector.

  1. 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

  1. 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)
A202812E01

  1. Disconnect the power management control ECU connector.

  1. Disconnect the clutch start switch assembly connector.

  1. 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

    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. Reconnect the power management control ECU connector.

  1. 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)
A201363E01

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

  1. Disconnect the ECM connector.

  1. Disconnect the clutch start switch assembly connector.

  1. 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

    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. Reinstall the ST relay connector.

  1. Reconnect the ECM connector.

  1. 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
C193931E02

  1. Disconnect the park/neutral position switch connector.

  1. 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

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

  1. 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)
A202813E01

  1. Disconnect the power management control ECU connector.

  1. Disconnect the park/neutral position switch connector.

  1. 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

    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. Reconnect the power management control ECU connector.

  1. 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)
A201364E01

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

  1. Disconnect the ECM connector.

  1. Disconnect the park/neutral position switch connector.

  1. 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

    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. Install the ST relay.

  1. Reconnect the ECM connector.

  1. 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)
A201363E01

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

  1. Disconnect the ECM connector.

  1. Disconnect the clutch start switch assembly connector.

  1. 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

    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. Reinstall the ST relay.

  1. Reconnect the clutch start switch assembly connector.

  1. Reconnect the ECM connector.



B
Go to step 10
A

REPAIR OR REPLACE HARNESS OR CONNECTOR 

9.CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH ASSEMBLY - ECM - ST RELAY)
A201364E01

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

  1. Disconnect the ECM connector.

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

  1. 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

    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. Install the ST relay.

  1. Reconnect the ECM connector.

  1. 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)