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


A240776E01


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 6

C
Go to step 9

D
Go to step 10
A


2.READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL)

  1. Disconnect the engine stop and start ECU connector.

  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
NG
A
OK
B

  1. Reconnect the engine stop and start ECU connector.



B
REPLACE ENGINE STOP AND START ECU (Click here)
A


3.INSPECT CLUTCH START SWITCH ASSEMBLY
A159771E14

  1. Remove the clutch start switch assembly.

  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. Reinstall the clutch start switch assembly.



NG
REPLACE CLUTCH START SWITCH ASSEMBLY (Click here)
OK


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

  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

  1. Reconnect the power management control ECU connector.

  1. Reconnect the clutch start switch assembly connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


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

  1. Remove the ST relay.

  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

  1. Reconnect the clutch start switch assembly connector.

  1. Reconnect the ECM connector.

  1. Reinstall the ST relay connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

CHECK ENTRY AND START SYSTEM (Click here)  

6.INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY
C193931E02

  1. Remove the park/neutral position switch assembly.

  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. Reinstall the park/neutral position switch assembly.



NG
REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY (Click here)
OK


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

  1. Disconnect the power management control ECU 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
    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

  1. Reconnect the power management control ECU connector.

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



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


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

  1. Remove the ST relay.

  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

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

  1. Reconnect the ECM connector.

  1. Install the ST relay.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

CHECK ENTRY AND START SYSTEM (Click here)  

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

  1. Remove the ST relay.

  1. Disconnect the clutch start switch assembly connector.

  1. Disconnect the ECM 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

    Result 
    Result
    		Proceed to
    Outside standard range
    		A
    Within standard range
    		B

  1. Reconnect the ECM connector.

  1. Reconnect the clutch start switch assembly connector.

  1. Reinstall the ST relay.



B
Go to step 11
A

REPAIR OR REPLACE HARNESS OR CONNECTOR 

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

  1. Remove the ST relay.

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

  1. Disconnect the ECM 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

    Result 
    Result
    		Proceed to
    Outside standard range
    		A
    Within standard range
    		B

  1. Reconnect the ECM connector.

  1. Reconnect the park/neutral position connector.

  1. Install the ST relay.



B
Go to step 11
A

REPAIR OR REPLACE HARNESS OR CONNECTOR 

11.INSPECT BATTERY

  1. Check that the battery is not depleted.

    OK:
    Battery is not depleted.



NG
REPLACE BATTERY
OK


12.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)