Pinpoint Test Instructions

Do not perform any of the following pinpoint tests unless instructed to do so by the Quick Tests. Each pinpoint test assumes that a fault (malfunction) has been detected in the system with direction to enter a specific repair routine. Conducting any pinpoint test without direction from the quick test procedures may produce incorrect results and replacement of satisfactory components. Correct test results are dependent on the proper operation of non-related EEC components/systems. Do not replace any components unless the test result indicates that they should be replaced.
If more than one service code is received, always start the service with the first code received. Do not measure voltage or resistance at the processor or connect any test lights to the processor unless specified to do so with the quick and/or pinpoint test procedures. Isolate both ends of a circuit, then turn ignition switch to OFF position when checking for shorts or circuit continuity, unless specified to do otherwise with the quick and/or pinpoint test procedures. Disconnect solenoids and/or switches from the harness before measuring for continuity or resistance. When using the pinpoint tests, follow each step in order, starting from the first step in the appropriate test. Follow each step until the fault (malfunction) is found. After completing any repairs to the EEC-IV system, ensure that all components are properly connected and repeat functional test. During the test procedure, an open is defined as any resistance obtained greater than 5 ohms, unless otherwise specified within the quick and/or pinpoint test charts. A short is defined as any resistance value obtained of less than 10,000 ohms to ground, unless otherwise specified within the quick and/or pinpoint test charts.