FixVault

Heated Oxygen Sensor Heater Resistance

NOTE: Bank No. 1 refers to bank that includes cylinder No. 1. Bank No. 2 refers to bank without cylinder No. 1. Sensor No. 1 refers to sensor closest to engine block. Sensor No. 2 refers to sensor behind catalytic converter.
  1. On LS400, go to next step. On GS300 and SC300, locate heated oxygen sensor to be tested. See Fig 1. Connector for bank No. 2, sensor No. 2 is located under front passenger's seat carpet. On GS400 and SC400, one sensor is located in each exhaust manifold and one sensor is located behind each catalytic converter. Connector for bank No. 1, sensor No. 2 is located under driver's seat carpet. Connector for bank No. 2, sensor No. 2 is located under front passsenger's seat carpet. Go to step  3.
  2. On LS400, one sensor is located in each exhaust manifold and one sensor is located behind each catalytic converter. Connector for bank No. 1, sensor No. 2 is located under driver's seat carpet behind rear air duct. Connector for bank No. 2, sensor No. 2 is located under front passsenger's seat carpet behind rear air duct. Go to next step.
  3. On all models, disconnect oxygen sensor connector to be tested. Measure resistance between terminals B+ and HT at oxygen sensor connector. See Fig 2. Replace oxygen sensor if resistance is not 11-16 ohms.
Fig 1: Locating Heated Oxygen Sensors (GS300 & SC300)
G99C51336Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 2: Testing Oxygen Sensor Heater
G98B11545Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002