KOEO & KOER SELF-TEST Codes

All service codes are 2- or 3-digit numbers. Transmission-related service codes are all 3-digit codes. ECA outputs codes one digit at a time. These codes indicate current faults in system and should be serviced in order of appearance. Use CODE REFERENCE table under SERVICE CODE REFERENCE  to find correct CIRCUIT TEST. Codes are shown as voltage pulses (needle sweeps) on an analog Volt-Ohmmeter (VOM). See Figure .

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, and 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 single 1/2-second sweep (Separator) and another 6-second delay. Record codes in order received.

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 Figure . If using CHECK ENGINE light, service codes are displayed as flashes.