Starter Signal Circuit

FA20 ENGINE CONTROL: SFI SYSTEM: Starter Signal Circuit; 2013 MY FR-S [03/2012 -]
- Starter Signal Circuit

DESCRIPTION

While the engine is being cranked, the current from the ST relay flows to the ECM STSW2 terminal. The starter start signal flowing to the STSW2 terminal is mainly used to increase the fuel injection quantity while the engine is starting.

WIRING DIAGRAM





INSPECTION PROCEDURE

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

PROCEDURE

1. CHECK WHETHER ENGINE CAN BE CRANKED

(a) Check if the engine can be cranked.

Result





B -- READ VALUE USING TECHSTREAM (ST SIGNAL)
A -- Continue to next step.

2. READ VALUE USING TECHSTREAM (STARTER SIGNAL)

(a) Connect the Techstream to DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / Starter Signal.

(e) Check the value displayed on the Techstream when the ignition switch is turned to the ON and START positions.

OK





NG -- INSPECT IGNITION OR STARTER SWITCH ASSEMBLY
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (ECM - ST RELAY - STARTER ASSEMBLY)

(a) Disconnect the ECM connector.

(b) Disconnect the starter assembly connector.

(c) Remove the ST relay from the engine room relay block assembly.

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

Standard Resistance (Check for open):





Standard Resistance (Check for short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY

(a) Inspect the ignition or starter switch assembly Testing and Inspection.

NG -- REPLACE IGNITION OR STARTER SWITCH ASSEMBLY Removal
OK -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - ST RELAY)

(a) Disconnect the ignition or starter switch assembly connector.

(b) Remove the ST relay from the engine room relay block assembly.

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

Standard Resistance (Check for open):





Standard Resistance (Check for short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

6. INSPECT TERMINAL VOLTAGE (+B OF IGNITION OR STARTER SWITCH ASSEMBLY)

(a) Disconnect the ignition or starter switch assembly connector.









(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Result





B -- INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY

C -- INSPECT CLUTCH START SWITCH ASSEMBLY

A -- REPAIR OR REPLACE HARNESS OR CONNECTOR

7. INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY

(a) Inspect the park/neutral position switch assembly Component Tests and General Diagnostics.

NG -- REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY Removal
OK -- Continue to next step.

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

(a) Disconnect the park/neutral position switch assembly connector.

(b) Remove the INHIBITOR relay from the engine room relay block assembly.

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

Standard Resistance (Check for open):





Standard Resistance (Check for short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

9. CHECK HARNESS AND CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - INHIBITOR RELAY)

(a) Disconnect the ignition or starter switch assembly connector.

(b) Remove the INHIBITOR relay from the engine room relay block assembly.

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

Standard Resistance (Check for open):





Standard Resistance (Check for short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

10. CHECK HARNESS AND CONNECTOR (INHIBITOR RELAY - ST RELAY)

(a) Remove the INHIBITOR relay and ST relay from the engine room relay block assembly.

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

Standard Resistance (Check for open):





Standard Resistance (Check for short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

11. CHECK HARNESS AND CONNECTOR (ECM - ST RELAY)

(a) Disconnect the ECM connector.

(b) Remove the ST relay from the engine room relay block assembly.

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

Standard Resistance (Check for open):





Standard Resistance (Check for short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

12. INSPECT CLUTCH START SWITCH ASSEMBLY

(a) Inspect the clutch start switch assembly Component Tests and General Diagnostics.

NG -- REPLACE CLUTCH START SWITCH ASSEMBLY Removal
OK -- Continue to next step.

13. CHECK HARNESS AND CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - CLUTCH START SWITCH)

(a) Disconnect the ignition or starter switch assembly connector.

(b) Disconnect the clutch start switch assembly connector.

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

Standard Resistance (Check for open):





Standard Resistance (Check for short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

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

(a) Disconnect the clutch start switch assembly connector.

(b) Remove the ST relay from the engine room relay block assembly.

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

Standard Resistance (Check for open):





Standard Resistance (Check for short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

15. CHECK HARNESS AND CONNECTOR (ECM - ST RELAY)

(a) Disconnect the ECM connector.

(b) Remove the ST relay from the engine room relay block assembly.

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

Standard Resistance (Check for open):





Standard Resistance (Check for short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

16. READ VALUE USING TECHSTREAM (ST SIGNAL)

(a) Connect the Techstream to DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / Starter Signal.

(e) Check the value displayed on the Techstream when the ignition switch is turned to the ON and START positions.

OK





Result





B -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures
A -- Continue to next step.

17. CHECK HARNESS AND CONNECTOR (ECM - ST RELAY)

(a) Disconnect the ECM connector.

(b) Remove the ST relay from the engine room relay block assembly.

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

Standard Resistance (Check for open):





Standard Resistance (Check for short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal