MPI Inspection Test: Notes

1. Check voltage standards of each terminal as specified in MPI SYSTEM CHECK CHARTS at the end of this article. Make sure ignition switch, vehicle operation and conditions are observed as called out in procedure.
2. Turn ignition switch to "OFF" position and remove ECU cover. Remove body side harness connectors "A" (24 poles) and "B" (13 poles) from ECU. On ECI checker, set check switch to "OFF" position and select switch to "A". Connect ECI connector by using MPI harness connector to ECU and body harness connectors. See Figure .
3. Position ECI checker on front passenger seat. Check output monitor operating condition (on or off) by alternating ignition switch from "OFF" to "ON" position. Monitor operating condition should be as follows: Airflow Sensor - ON, Injector Pulse - OFF, Oxygen Sensor - OFF. Perform checks according to charts.
4. If checker reading varies from specifications, check corresponding sensor and related electrical wiring. After component repair or replacement, recheck to confirm system performance.
5. Airflow sensor and injector pulse may be inspected by output monitors as well. Set select switch to "B". Normal operation is as follows: airflow sensor and injector are always flashing with check switch at 1 through 12. Oxygen sensor is flashing at closed loop zone. The flashes will be so short that light will appear to be continuously on.
6. Set check switch of ECI checker to "OFF" position. Set ignition switch to "OFF" position. Carefully separate connectors of ECI checker from ECU and body side harness connectors. Connect body side harness connector to ECU. Install ECU cover.