How To Use System Tests
- DO NOT perform any SYSTEM TEST unless specifically instructed by a QUICK TEST procedure. Follow each test step in order until fault is found. DO NOT replace any part unless directed to do so. When more than one DTC is retrieved, start with first DTC displayed.
- SYSTEM TESTS ensure electrical circuits are okay before sensors or other components are replaced. Always test circuits for continuity between sensor, PCM or TCM. Test all circuits for short to power, opens or short to ground. Voltage Reference (VREF) and Voltage Power (VPWR) circuits should be tested with ignition on or as specified in SYSTEM TESTS.
- DO NOT measure voltage or resistance at PCM or TCM, as harness and connector are easily damaged. DO NOT connect any type of test light unless specified in testing procedure. All measurements are made by probing rear of connector (wiring harness side), unless otherwise instructed. Isolate both ends of a circuit and turn ignition off when checking for shorts or continuity, unless instructed otherwise.
- 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 .
- An open circuit is defined as a resistance reading of greater than 5 ohms. This specification tolerance may be too high for some items in EEC system. If resistance approaches 5 ohms, always clean suspected connector and coat with protective dielectric silicone grease. A short is defined as a resistance reading of less than 10 k/ohms to ground, unless stated otherwise in SYSTEM TEST.