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Home >> Merkur >> 1988 >> XR4Ti Standard >> Repair and Diagnosis >> Engine Performance >> System >> EEC-IV System >> Description & Operation >> Outputs >> Self-Test Output (STO)
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Self-Test Output (STO)

STO is a circuit in the ECA which transmits service codes, in the form of timed pulses, to either a VOM or STAR tester hooked-up at SELF-TEST connector. These pulses are read as diagnostic codes.