If the check engine light is on read the codes, this is always the first step, here's how, Post all codes found, and I will tell you what's next.
KOEO & KOER SELF-TEST Codes
PCM outputs codes one digit at a time. Record codes in order received. These codes indicate current
faults in system and should be serviced in order of appearance. Use SERVICE CODE-TO-TEST
MENUS to find correct CIRCUIT TEST.
If using VOM, pay careful attention to length of pauses in order to read codes correctly. A 1/2-second
pause occurs between number of sweeps in a digit. A 2-second pause occurs between digits in a code.
A 4-second pause occurs between each code. KOEO codes are separated from Continuous Memory
codes by a 6-second delay, a 1/2-second sweep (separator) and another 6-second delay. See Fig. 1.
If using MIL/CHECK ENGINE light, service codes are displayed as flashes. On Continental, message
center may be used to display codes. See Fig. 2.
Scan tester, if used, will count pulses and display them as a digital code. STAR Series Tester will add
a zero (0) to single-digit Separator Code (10) and Dynamic Response Code (10). Dynamic Response
Code is displayed in KOER SELF-TEST. See Fig. 1.
Single 1/2-second separator pulse is issued 6-9 seconds after last KOEO code. Continuous Memory
Codes (soft faults) are then displayed 6-9 seconds after 1/2-second separator pulse. Some digital test
equipment may display separator code as "10" instead of "1".
A Code 11 or 111 indicates no service codes were recorded in that portion of test; system passes that
portion of test. If Code 11 or 111 is not retrieved in KOEO SELF-TEST, codes retrieved during
KOER SELF-TEST may not be valid. Code 11 or 111 (pass code) must be obtained in KOEO SELFTEST.
A Code 11-1-11or 111-1-111 output during KOEO SELF-TEST indicates no KOEO code or
Continuous Memory Code was recorded.
Continuous Memory Codes
These codes result from information stored by PCM during continuous self-test monitoring. Codes are
displayed after separator pulse code in KOEO SELF-TEST. Use these codes for diagnosis only when
KOEO SELF-TEST and KOER SELF-TEST result in Code 11 or 111 (pass code) and all steps under
QUICK TEST are successfully completed. (A few codes are exceptions which may be checked after
KOEO codes have been repaired). These codes indicate faults recorded within last 40 engine starts
(80 engine starts on some models). Fault may or may not be currently present. See SERVICE CODETO-
At start of KOEO SELF-TEST and after Wide Open Throttle (WOT) request in KOER SELF-TEST,
PCM outputs short bursts of information, known as FAST CODES, which were used by manufacturer
during assembly. With most equipment, these code bursts are not visible; an entire code sequence
lasts less than 1/2 second. If this fluctuation is visible on test equipment, ignore it.
Fig. 2: Message Center Self-Test (Continental)
Courtesy of FORD MOTOR CO.
Tuesday, May 11th, 2010 AT 10:13 AM