Fuel Injector Circuit Tests

Check Fuel Injector Operation - Using a stethoscope, ensure there are injector operating sounds while engine is cranking. If operating sounds are not heard, go to next step. If operating sounds are heard, verify fuel pressure. See FUEL PRESSURE under FUEL SYSTEM.
Check Fuel Injector Power Circuit - Turn ignition off and disconnect each fuel injector connector. Ensure there are at least 10 volts between each injector connector terminal and ground. If at least 10 volts are present, go to next step. If at least 10 volts are not present, repair harness or connectors as necessary.
Check Fuel Injectors - Measure resistance between connector terminals of each fuel injector. If resistance is 11-12 ohms, go to next step. If resistance is not 11-12 ohms, replace injector(s).
Measure Voltage Between ECU Connectors & Fuel Injectors - Connect fuel injector connectors and turn ignition on. Measure voltage between ECU connector terminals and ground. See the FUEL INJECTION & ECU HARNESS VOLTAGE TESTING table. If at least 5 volts are present, go to next step. If at least 5 volts are not present, repair or replace harness or connectors as necessary.
Check ECU Ground Circuit Resistance - Disconnect ECU 26-pin connector. Measure resistance between connector terminal No. 24 (Blue/Black wire) and ground and between terminal No. 25 (Black/Yellow wire) and ground. If resistance is more than zero ohms, repair harness or connectors between ECU and ground. Inspect ECU connector terminal. If ECU connector terminal is okay, replace ECU.

FUEL INJECTION & ECU HARNESS VOLTAGE TESTING

ECU Terminal No.

Wire Color

Engine Cylinder No.

13 ⁽¹⁾

(WHT)

12 ⁽¹⁾

(WHT/BLK)

11 ⁽¹⁾

(WHT/RED)

26 ⁽¹⁾

(WHT/BLU)

1 ⁽²⁾

(WHT/GRN)

12 ⁽²⁾

(WHT/YEL)

⁽¹⁾	Yellow ECU 26-pin connector.

⁽²⁾	Yellow ECU 22-pin connector.