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Home >> Ford >> 1988 >> Taurus MT5 >> Repair and Diagnosis >> Engine Performance >> System >> 2.5L EEC IV Tests W/Codes >> Quick Test >> Key On/Engine Off (KOEO) Self-Test >> Test Procedure
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Test Procedure

  1. Turn ignition switch to "OFF" position. Ensure all procedures of PREPARATION  and EQUIPMENT HOOK-UP  have been followed. Engine should be at normal operating temperature.
  2. Ensure VOM or tester is connected properly. Turn ignition on. If Star Tester is being used latch center button in down position at this time.
  3. The ECA will run through a test cycle, opening and closing various solenoids and switches. After the completion of the test cycle the codes will appear. Record all codes.
  4. The first set of codes to appear are the KOEO SELF-TEST codes; they will be repeated twice, followed by the Separator Pulse signal and then the CONTINUOUS MEMORY codes. These codes will also be repeated twice.
  5. A KOEO code 11 indicates the system has passed the self test. A code 11 must be present before continuing. Disregard any CONTINUOUS MEMORY codes at this time. Service KOEO codes (in the order they appear) and rerun KOEO test until a code 11 is displayed. See KEY ON ENGINE OFF (KOEO) CODE-TO-CKT TEST  service code tables.
  6. Whenever a repair is made, repeat QUICK TEST  . If no codes are displayed, repeat SELF-TEST to verify that other service codes are still present.
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