How To Use Circuit Tests
- 1) Ensure all non-EEC related faults found while performing steps in the BASIC TESTING article have been corrected. Follow each test step in order until fault is found. When more than one code is retrieved, start with first code displayed.
- 2) CIRCUIT TESTS ensure electrical circuits are okay before sensors or other components are replaced. Always test circuits for continuity between sensor and PCM.
- 3) Manufacturer recommends making voltage or resistance at breakout box, as PCM harness and connectors are easily damaged. PCM harness connector illustration is provided for reference purposes. See Fig 1.
- 4) DO NOT connect any test light unless specified in testing procedure. All measurements are made by probing rear of component connector (wiring harness side). With ignition off, isolate both ends of a circuit when checking for shorts or continuity, unless instructed otherwise.
- 5) Disconnect solenoids and switches from harness before measuring continuity and resistance or applying voltage. After each repair, check all component connections and repeat QUICK TEST .
- 6)
An open circuit is defined as a resistance reading of greater than 5 ohms. If resistance approaches 5 ohms, always clean suspect connector and coat it with protective dielectric silicone grease. A short is defined as a resistance reading of less than 10,000 ohms to ground, unless stated otherwise in CIRCUIT TEST.
NOTE: In following tests, circuit diagrams and illustrations are courtesy of Ford Motor Co.