Oxygen Sensor Relay: Description and Operation

NOTE: The feedback inhibit relay and related wiring are only on vehicles up to VIN 153559.

PURPOSE
The feedback inhibit relay functions to cancel ECU oxygen sensor input when vehicle gear selector is in "P" or "N." Gear position is signalled by a neutral switch.

OPERATION
Inhibiting ECU oxygen sensor input creates an "open loop" condition, richening the fuel mixture for a more stable idle. In order to cancel this function for emissions or diagnostic testing, a jumper plug is located in the feedback monitor socket assembly.

LOCATION
Right rear corner of engine compartment.