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Fuel Injector Circuit

  1. Turn ignition off. Pull back the right front floor mat. Remove ECM protective cover. Connect a Check Harness (09990-01000) between ECM and harness. See USING CHECK HARNESS  under INTRODUCTION. Turn ignition on.
  2. Measure voltage between chassis ground and terminals No. 15-20 of ECM connector "B" (Red/Black, Red, Red/White, Red/Green, Red/Yellow and Red/Blue wires). To identify ECM connectors and terminals, see Figure.
  3. If battery voltage is measured at all terminals, go to next step. If battery voltage is not measured at all terminals, check IG2 (ignition main) relay. See RELAYS  under MODULES, MOTORS, RELAYS & SOLENOIDS. If IG2 relay is okay, repair harness between IG2 relay and battery.
  4. Check for continuity between chassis ground and terminals No. 79 and 80 (White/Black wires) of ECM connector "B". If there is no continuity, repair open White/Black wires. If there is continuity, check for open circuits between IG2 relay and injectors, and between injectors and ECM.
  5. If circuits are okay, measure injector resistance and volume. See FUEL INJECTOR RESISTANCE  and FUEL INJECTOR VOLUME. If resistance and volume are as specified, replace ECM.
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