Reading Self-Test Codes: Notes

Service codes are transmitted to Pin No. 4 (Self-Test Output) of SELF-TEST connector in the form of timed pulses. All service codes are 2 digit numbers which are generated one digit at a time. Codes are shown as voltage pulses (needle sweeps) on an analog volt/ohmmeter (VOM).

If a VOM is being used, careful attention to the length of the pauses is necessary in order to read the codes correctly. There will be a 2 second pause between each DIGIT in a code. There will be a 4 second pause between each CODE. The continuous memory codes are separated from the functional test service codes by a 6-second delay, a single 1/2 second sweep, and another 6-second delay.

If a Self-Test Automatic Read-Out (STAR) tester is used, it will count the pulses and display them as a digital code. The STAR tester will add a zero (0) to single digit codes.