Equus 3145 - Digital Ford Code Reader (1981 - 1995) - Manual (Page 28)

Retrieving Codes
KOEO TEST PROCEDURES (EEC-IV SYSTEMS)
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tests are designed to activate components and test their
operation only with the Key On and Engine Running. Do
not take short cuts. If you fail to perform a test, or you
perform a test out of sequence, you might miss a problem
that is only detected during that particular test procedure.
To properly receive Diagnostic Trouble Codes from the
Ford computer control system, perform the Self Tests in
the following order:
1. Key On Engine Off (KOEO) Self Test
2. Ignition Timing Check (vehicle Ignition Timing System
must be working properly before the KOER Self Test can
be performed)
3. Key On Engine Running (KOER) Self Test
IMPORTANT:
• To retrieve Diagnostic Trouble Codes from EEC-IV
Systems proceed to the next section below.
• To retrieve Diagnostic Trouble Codes from MCU systems
proceed to page 66.
KEY ON ENGINE OFF (KOEO) TEST PROCEDURES
(EEC-IV SYSTEMS)
NOTE: During the KOEO Self Tests two groups of codes will be
sent to the Code Reader by the vehicle’s computer.
• The first groups of codes sent to the Code Reader are called
"KOEO Self Test codes",
• followed by the second group called "Continuous Memory
Codes".
NOTE: Before the computer sends the second group of codes to
the Code Reader, it first sends a “separator code” (code 10) to
separate the first group of codes from the second group.
• Always observe safety precautions before and during
testing process.
• ALWAYS check Code Reader battery before retrieving
fault codes.
• Fix any known mechanical problems before this test.
1. Warm-up engine to normal operating temperature before
performing this test.
2. Turn ignition off.
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