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FUEL INJECTOR CIRCUIT

FUEL INJECTOR CIRCUIT

Important

After repair or replacement of faulty parts, conduct Clear Memory Mode and Inspection Mode .


WIRING DIAGRAM:


CHECK OPERATION OF EACH FUEL INJECTOR.

While cranking the engine, check that each fuel injector emits “operating” sound. Use a sound scope or attach a screwdriver to injector for this check.

Does the fuel injector emit “operating” sound?

Yes

Check the fuel pressure.


No


CHECK POWER SUPPLY TO EACH FUEL INJECTOR.

Turn the ignition switch to OFF.

Disconnect the connector from fuel injector.

Turn the ignition switch to ON.

Measure the power supply voltage between the fuel injector terminal and engine ground.

Connector & terminal

#1 (E5) No. 2 (+) — Engine ground (−):

#2 (E16) No. 2 (+) — Engine ground (−):

#3 (E6) No. 2 (+) — Engine ground (−):

#4 (E17) No. 2 (+) — Engine ground (−):

Is the voltage more than 10 V?

Yes


No

• Repair the harness and connector.

•
Note

In this case, repair the following:

• Open circuit in harness between main relay and fuel injector connector

• Poor contact in main relay connector

• Poor contact in coupling connector

• Poor contact in fuel injector connector



CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR.

Disconnect the connector from ECM.

Measure the resistance of harness between ECM and fuel injector connector.

Connector & terminal

(B84) No. 1 — (E5) No. 1:

(B137) No. 6 — (E16) No. 1:

(B137) No. 5 — (E6) No. 1:

(B137) No. 4 — (E6) No. 1:

Is the resistance less than 1 Ω?

Yes


No

• Repair the harness and connector.

•
Note

In this case, repair the following:

• Open circuit in harness between ECM and fuel injector connector

• Poor contact in coupling connector



CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR.

Measure the resistance of harness between ECM and fuel injector connector.

Connector & terminal

(B84) No. 1 — Chassis ground:

(B137) No. 6 — Chassis ground:

(B137) No. 5 — Chassis ground:

(B137) No. 4 — Chassis ground:

Is the resistance less than 1 Ω?

Yes

Repair the ground short circuit in harness between ECM and fuel injector connector.


No


CHECK EACH FUEL INJECTOR.

Turn the ignition switch to OFF.

Measure the resistance between each fuel injector terminals.

Terminals

No. 1 — No. 2:

Is the resistance 5 — 20 Ω?

Yes


No

Replace the faulty fuel injector.


CHECK POOR CONTACT.

Check poor contact in ECM connector.

Is there poor contact in ECM connector?

Yes

Repair the poor contact in ECM connector.


No

Inspection using “General Diagnostic Table”.