Diagnostic Formats

There are 2 diagnostic formats used to test and service the EEC-IV system: QUICK TEST and CIRCUIT TESTS. A DIAGNOSIS BY SYMPTOM  is available to identify specific problems and reference specific CIRCUIT TESTS, if no Key On Engine Off (KOEO) or Key On Engine Running (KOER) fault code is identified.

Always start with the QUICK TEST procedures before attempting any CIRCUITS TESTS. The QUICK TEST procedure is designed to allow the technician to identify problems and retrieve service codes. The CIRCUIT TESTS give procedures for testing circuits and checking sensors and actuators. If a vehicle passes the QUICK TEST procedures, and there are no driveability problems, the EEC-IV system is okay. Problem exists somewhere else besides the EEC-IV system. If an intermittent driveability problem exists, use the KOER "Wiggle" Test procedure to set a code or identify the problem.