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Ecu Power Supply & Ground Tests

  1. Check Ground & ECU Power Supply  - Turn ignition off and disconnect ECU connector. Measure resistance between ECU harness side connector terminals No. 30 (Black/Red wire), No. 42 (Black/Red wire), No. 44 (Black wire), No. 51 (Black wire) and ground. Ensure there is less than 10 ohms resistance between each terminal and ground. If resistance is not as specified, verify proper ground connection at right intake manifold ground terminal. Ensure there is proper connection between body harness and engine harness connectors. Repair ground connection, harness or connectors as necessary.
  2. Check ECU Power Supply Circuit  - Turn ignition on (engine off). Measure voltage between ECU harness side connector terminals No. 27 (Black/White wire), No. 29 (White wire), No. 41 (White wire), No. 49 (Red/Blue wire) and ground. Ensure there is 10 volts are present between each terminal and ground. If 10 volts are present, see LOYALE under IGNITION CONTROL SYSTEM TEST. If 10 volts are not present, inspect battery terminals, fuse, ignition relay and ignition switch. Repair or replace component(s) as necessary. If components are okay, repair harness or connectors as necessary.
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