DR-4B Oxygen Sensor Wire to SMEC For Open Circuit

Complete Driveability Test 4, Step A before proceeding.

1. With diagnostic read-out tool connected to engine test connector, turn ignition switch Off, then disconnect oxygen sensor connector.
2. Connect a jumper wire to black wire/dark green wire of harness end of connector.
3. Place system in Sensor Test Mode 02.
4. Touch other end of jumper wire to positive post of battery, then to negative battery post.
5. If display read-out indicates 5 volts when touching positive post, replace oxygen sensor.
6. If display read-out is .4 volt, check black/dark green wire from oxygen sensor connector for an open circuit.