Diagnostic Systems for the 1993-1995 Mazda 626
MECS-II (1981-1995) All Models (except 93-95 2.0L automatics)
EEC-IV (1993-1995) 2.0L Automatics Only
OBD-II (1996-2002) All Models (Nothing in this topic applies to you, get an OBD-II code scanner) This article covers both MECS-II (OBD-I) & EEC-IV diagnostics for 1993-1995 Mazda 626, Mazda MX-6, Ford Probe, and other vehicles. You will need to figure out if you have either MECS-II or EEC-IV to get the most out of this article.
Short history of OBD-I diagnostic systems:
OBD-I is a generic term given to any diagnostic system prior to 19