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Home >> Cadillac >> 1990 >> Seville Base, 4T60/ME9 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> ECM Trouble Code Charts >> ECM Code EO12: No Distributor (Tach) Signal >> Failure Conditions:

Failure Conditions:

If ECM does not see distributor reference pulses for 4 seconds with crank input to ECM at system voltage, Code EO12 will be set.