LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2003 >> GX 470 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Sensors & Switches >> Heated Oxygen Sensor
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Heated Oxygen Sensor

  1. Four heated oxygen sensors are used, one on each exhaust manifold, and one on each exhaust pipe behind catalytic converter. On driver's side, heated oxygen sensor on exhaust manifold may be referred to as bank 1 sensor 1, and heated oxygen sensor on exhaust pipe behind catalytic converter may be referred to as bank 1 sensor No 2. On passenger's side, heated oxygen sensor on exhaust manifold may be referred to as bank 2 sensor 1, and heated oxygen sensor on exhaust pipe behind catalytic converter may be referred to as bank 2 sensor 2.
  2. To test heater on heated oxygen sensor, disconnect electrical connector at appropriate heated oxygen sensor and note heated oxygen sensor terminals. See Fig 1. Illustration is for sensor 1.
  3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. See Fig 1. Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C). Check that there is no continuity between terminals HT and E1. Replace heated oxygen sensor if there is continuity.
  4. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). Retrieve DTCs and perform appropriate diagnostic test. See SELF-DIAGNOSTICS - GX470 article.
Fig 1: Identifying Heated Oxygen Sensor Terminals (Sensor 1)
G00248005Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002