Sfi System Starter Signal Circuit
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
When using intelligent tester:
READ DATA LIST (STA SIGNAL)
CHECK HARNESS AND CONNECTOR (ECM - IGNITION SWITCH)
When not using intelligent tester:
CHECK ECM (STA VOLTAGE)
CHECK HARNESS AND CONNECTOR (ECM - IGNITION SWITCH)
SFI SYSTEM - Starter Signal Circuit |
DESCRIPTION
When the engine is cranked, the intake air flow becomes slow, so fuel vaporization is poor. A rich mixture is therefore necessary in order to achieve good startability. While the engine is being cranked, the battery voltage is applied to terminal STA of the ECM. The starter signal is mainly used to increase the fuel injection volume for starting and after-start injection control.
WIRING DIAGRAM
INSPECTION PROCEDURE
When using intelligent tester:
1.READ DATA LIST (STA SIGNAL) |
Connect the intelligent tester to the DLC3.
Turn the ignition switch ON and turn the intelligent tester ON.
Enter the following menus: Powertrain / Engine and ECT / Data List / Starter Signal.
Check the result when the ignition switch is turned to ON and START.
- Result:
Ignition Switch Position
| STA Signal
|
ON
| OFF
|
START
| ON
|
| PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
|
|
2.CHECK HARNESS AND CONNECTOR (ECM - IGNITION SWITCH) |
Disconnect the E8 ECM connector.
Disconnect the I8 ignition switch connector.
Measure the resistance of the wire harness side connectors.
- Standard resistance:
Tester Connection
| Specified Condition
|
E8-12 (STA) - I8-7 (ST2)
| Below 1 Ω
|
E8-12 (STA) or I8-7 (ST2) - Body ground
| 10 kΩ or higher
|
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
When not using intelligent tester:
1.CHECK ECM (STA VOLTAGE) |
Turn the ignition switch ON.
Measure the voltage of the ECM connectors.
- Standard voltage:
Tester Connection
| Specified Condition
|
E8-12 (STA) - E11-3 (E1)
| 0 V
|
Measure the voltage of the ECM connectors when the engine is cranked.
- Standard voltage:
Tester Connection
| Specified Condition
|
E8-12 (STA) - E11-3 (E1)
| 6 V or more
|
| PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
|
|
2.CHECK HARNESS AND CONNECTOR (ECM - IGNITION SWITCH) |
Disconnect the E8 ECM connector.
Disconnect the I8 ignition switch connector.
Measure the resistance of the wire harness side connectors.
- Standard resistance:
Tester Connection
| Specified Condition
|
E8-12 (STA) - I8-7 (ST2)
| Below 1 Ω
|
E8-12 (STA) or I8-7 (ST2) - Body ground
| 10 kΩ or higher
|
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|