Toyota 1 MZ–FE Manual page 482

EG2–482
1MZ–FE ENGINE – CIRCUIT INSPECTION
DIAGNOSTIC CHART
Check voltage of terminals HTR, HTS, HTL.
Check and replace ECM.
Check resistance of heated oxygen sensor heater.
Replace heated oxygen sensor.
Check and repair harness or connector between main relay
and heated oxygen sensor and ECM.
WIRING DIAGRAM