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Power Circuits

  1. Using DVOM, check for battery voltage between ECM continuous power terminal(s) and ground. If battery voltage is not present, check for open fuse or fusible link. If fuse or fusible link is okay, check for open in circuit between ECM continuous power terminal and power source.
  2. Turn ignition switch to RUN position. Using DVOM, check for battery voltage between ECM ignition power terminals and ground. If battery voltage is not present, check IGN fuse. If fuse is okay, check for open in circuit between battery and ignition switch, and between ignition switch and ECM ignition power terminal. If circuits are okay, check for defective ignition switch.
  3. Connect DVOM between ground and ECM starter (crank) signal terminal. Place gearshift lever in Park. Turn ignition switch to START position. Battery voltage should be present only when ignition switch is in START position.
  4. If voltage is not present, check CRANK fuse or fusible link between ignition switch and ECM starter (crank) signal terminal. If fuse or fusible link is okay, check for open in circuit between ignition switch and ECM starter (crank) signal terminal, or check for defective ignition switch.
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