Diagnostic Tools

The EFC system requires a circuit tester, stethoscope and a dry-cell battery for diagnosis. The circuit tester is used to measure voltage and resistance of check connectors. It is also used to measure resistance of duty solenoids and vacuum (pressure) sensor after lead connectors are unplugged. Stethoscope or vinyl tube is used to check operating sound from duty solenoid valves. The dry-cell battery is used to test O2 sensor and its wiring for defects.