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Home >> Mitsubishi >> 1990 >> Precis Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests - PFI >> Relays, Solenoids & Motors >> Relays >> MPI Control Relay
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MPI Control Relay

  1. For relay location, see MPI CONTROL RELAY LOCATION  table. Check for battery voltage at terminal No. 1 of relay connector. See Fig 1 .
  2. If battery voltage is present, go to step 3). If battery voltage is not present, check circuit between relay terminal No. 1 and battery, including 20A MPI fuse in engine compartment fuse panel.
  3. Disconnect wiring harness connector at relay. Remove relay. Check continuity between terminal No. 1 and terminals No. 2, 3, and 4. If there is no continuity, go to next step. If there is continuity, replace relay.
  4. Check diode operation between terminals No. 5 and 7. There should be continuity in only one direction (polarity). If there is continuity in only one direction, go to next step. If there is no continuity in either direction or if there is continuity in both directions, replace relay.
  5. Measure resistance between terminals No. 6 and 7. If resistance is approximately 35 ohms, go to next step. If resistance is not approximately 35 ohms, replace relay.
  6. Measure resistance between terminals No. 2 and 8, and terminals No. 3 and 8. In both tests, if resistance is approximately 95 ohms, go to next step. If resistance is not approximately 95 ohms, replace relay.
  7. Connect positive lead of 12-volt source to terminal No. 7 and negative lead to terminal No. 6. If there is continuity between terminals No. 1 and 4, go to next step. If there is no continuity, replace relay.
  8. Connect positive lead of 12-volt source to terminal No. 2 and negative lead to terminal No. 8. If there is continuity between terminals No. 1 and 4, go to next step. If there is no continuity, replace relay.
  9. Connect positive lead of 12-volt source to terminal No. 8 and negative lead to terminal No. 2. If there is continuity between terminals No. 1 and 4, go to next step. If there is no continuity, replace relay.
  10. Connect positive lead of 12-volt source to terminal No. 5 and negative lead to terminal No. 7. If there is continuity between terminals No. 1 and 2, and terminals No. 1 and 3, go to next step. If there is no continuity, replace relay.
    MPI CONTROL RELAY LOCATION

    Application Location
    Precis Above left kick panel
    Fig 1: Identifying MPI Control Relay Connector Terminals
    G90H17381Courtesy of MITSUBISHI MOTOR SALES OF AMERICA
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