Diagnostic Formats
WARNING: This page is about a different car, the 1993 Mazda Navajo. However, it is still accessible from the selected car via links, so may be relevant.
Use 2 diagnostic formats to test and service EEC-IV system: QUICK TEST and CIRCUIT TEST. QUICK TEST allows technician to identify problems and retrieve service codes. CIRCUIT TEST checks circuits, sensors and actuators.
Before starting any CIRCUIT TEST, follow all steps under QUICK TEST to find correct CIRCUIT TEST. If vehicle passes QUICK TEST and no driveability symptoms or intermittent faults exist, EEC-IV system is okay. Problem is in another system.