Equus 3145 - Digital Ford Code Reader (1981 - 1995) - Manual (Page 71)

Retrieving Codes
KOER SELF TEST (MCU SYSTEMS)
Chapter 4 68
NOTE: All retrieved codes will stay in the Code Reader's
memory and will only clear from the Code Reader's
memory if the Self Test procedure is performed again
(codes from a prior test will clear automatically when new
Self Test is performed) or if batteries are removed from the
Code Reader.
11. Go to page 72 for "FAULT CODE DEFINITION FOR
MCU SYSTEMS". Use the code definitions as a guide and
follow the manufacturer's service procedures in the
vehicle's service manual to troubleshoot and repair faults.
■ All KOEO Self Test codes that are received by the
Code Reader during the KOEO Self Test represent
problems that are present now (at the time the test is
performed). The related vehicle problems that cause
these codes to set must be repaired using the
procedures described in the vehicle's service manual.
12. After all repairs have been completed, repeat the KOEO
Self Test to verify the repair was successful. Do not
proceed to the KOER Self test until all the problems that
caused any KOEO fault codes to set are repaired.
KEY ON ENGINE RUNNING (KOER) SELF TEST (MCU
SYSTEMS)
IMPORTANT: The "Preliminary Procedures" (page 66) and
the "KOEO Self Test" (page 67) must be completed first, before
the KOER Self-Test is performed; otherwise test results might
be invalid.
When the KOER Self Test is activated, it tests the operation of
the actuators, relays, switches, etc. under actual engine
operating conditions. During this test, the computer sends
electrical signals to some of these devices and waits for their
response to see if its commands are carried out properly.
If the response from any of these devices is incorrect, that
particular device fails the test and the computer assigns a
numerical Fault Code that is specific to the device, circuit
and/or system where the problem was detected. All faults
detected during the KOER Self Test are sent to the Code
Reader as numerical fault codes for further evaluation.
• Always observe all safety precautions before and during
the testing process.
• ALWAYS check the Code Reader's batteries before
conducting the test.
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