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:

PROCEDURE

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

OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

NG

CHECK WIRE HARNESS (ECM - IGNITION SWITCH)

Disconnect the E9 ECM connector.
Disconnect the I6 ignition switch connector.

Measure the resistance of the wire harness side connectors.

Standard resistance

Tester Condition	Specified Condition
E9-12 (STA) - I6-7 (ST2)	Below 1 Ω
E9-12 (STA) or I6-7 (ST2) - Body ground	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

REPLACE ECM

When not using intelligent tester:

PROCEDURE

CHECK ECM (STA VOLTAGE)

Turn the ignition switch ON.

Measure the voltage of the ECM connectors.

Standard voltage

Tester Connection	Specified Condition
E9-12 (STA) - E12-3 (E1)	0 V

Measure the voltage of the ECM connectors when the engine is cranked.