STEP 2. Measure the power supply voltage at linear air-fuel ratio sensor harness side connector.
(1) Disconnect the linear air-fuel ratio sensor connector and measure at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal power supply line and ground.- Voltage should be battery positive voltage.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is battery positive voltage (approximately 12 volts) present?
Go to Step 3. Repair or replace the connector(s), or check and repair the harness of short to ground and open circuit in power supply line between MFI relay connector and linear air-fuel ratio sensor connector. Then go to Step 7.