1.CHECK HARNESS BETWEEN ECM AND ENGINE GROUND.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance of harness between ECM connector and chassis ground.
Connector & terminal
(B134) No. 1 — Chassis ground:
(B134) No. 2 — Chassis ground:
(B134) No. 3 — Chassis ground:
(B134) No. 4 — Chassis ground:
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Is the resistance less than 5 Ω?
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Repair the harness and connector.
NOTE:
In this case, repair the following item:
• Open circuit of harness between ECM connector and engine ground
• Poor contact of coupling connector
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2.CHECK FUEL INJECTOR DRIVE POWER SUPPLY.
1) Connect the connector to ECM.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM connector and chassis ground.
Connector & terminal
(B135) No. 25 (+) — Chassis ground (−):
(B135) No. 1 (+) — Chassis ground (−):
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Repair the poor contact of ECM connector.
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3.CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the ECM and fuel injectors #3 and #4.
3) Measure the resistance between ECM connector and chassis ground.
Connector & terminal
(B135) No. 25 — Chassis ground:
(B135) No. 26 — Chassis ground:
(B135) No. 1 — Chassis ground:
(B135) No. 3 — Chassis ground:
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Is the resistance 1 MΩ or more?
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Repair the short circuit to ground in harness between ECM connector and fuel injector connector.
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4.CHECK INSULATION CONDITION OF FUEL INJECTOR.
Measure the resistance between fuel injectors #3 and #4 and the engine ground.
NOTE:
Do not remove the fuel injectors from engine during measurement.
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Is the resistance 1 MΩ or more?
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Repair the poor contact of ECM connector.
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Replace the faulty fuel injector. 
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