Equus 3120 - OBD 2&1 Tool Kit - Manual (Page 55)

OBD2 & 1 53
E
Ford OBD1 Systems
CODE RETRIEVAL PROCEDURES - KOER TEST
■ The vehicle's computer is pro-
grammed to advance ignition timing
20° (±3°) above the vehicle's "base
timing" value, and to freeze this set-
ting for two minutes from the time the
"Perform Timing Check within 2 min-
utes" message displays. This allows
the user to check the computer's abil-
ity to advance ignition timing.
■ Within this two-minute period, follow instructions in the vehicle's
service repair manual to check the ignition timing with a timing
light and ensure that it is 20° above the specified base timing
value (±3°).
Example: If base timing specification is 10° BTDC, the acceptable tim-
ing light reading should be in the range of 27° to 33° BTDC.
Base-timing specifications can be found on the Vehicle
Emission Control Information (VECI) decal. The decal is
located under the hood or near the radiator. If the VECI decal
is missing or damaged, refer to your vehicle's service repair
manual for specifications.
8. If timing light readings are within the acceptable range:
■ Base timing and the vehicle computer's ability to advance timing
are working properly.
■ Proceed to the KOER Self-Test below.
9. If timing light readings are not within the acceptable range:
■ Base timing may be out of adjustment, or the computer may have
problems with the timing advance circuit.
■ Refer to the vehicle's service repair manual for procedures on
adjusting and/or repairing ignition timing. Repairs to ignition tim-
ing must be made before proceeding to the KOER Test.
Key on Engine Running (KOER) Self-Test
IMPORTANT: The KOEO Self-Test (page 48) must be per-
formed first, and a "pass code" (code 11 or 111) must be
obtained before performing the KOER Self-Test; otherwise,
results of the KOER Self-Test may be invalid.
Ignition timing and timing advance must be operating proper-
ly in order for the KOER Self-Test results to be considered
valid. Perform an Engine Timing check (page 51) before per-
forming the KOER Self-Test.
Check your vehicle thoroughly before performing any test.
See Before You Begin on page 17 for details.