A/F Sensor Heater Relay: Inspection

REMOVE RELAY BOX COVER
REMOVE A/F SENSOR HEATER RELAY (Marking: A/F)

Fig 1: Removing Relay Box Cover & A/F Sensor Heater Relay
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT A/F SENSOR HEATER RELAY
1. Inspect the relay continuity.
  1. Using an ohmmeter, check that there is continuity between terminals 1 and 2.
    If there is no continuity, replace the relay.
  2. Check that there is no continuity between terminals 3 and 5.
  If there is continuity, replace the relay.
2. Inspect the relay operation.
  1. Apply battery positive voltage to terminals 1 and 2.
  2. Using an ohmmeter, check that there is continuity between terminals 3 and 5.
  If there is no continuity, replace the relay.
REINSTALL A/F SENSOR HEATER RELAY
REINSTALL RELAY BOX COVER