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.

On GS300 and IS300, 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 GS430 and LS430, 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 behind driver's seat carpet. Connector for bank No. 2, sensor No. 2 is located under front passenger's seat carpet. On SC430, 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 behind driver's side console carpet. Connector for bank No. 2, sensor No. 2 is located behind front passenger's side console carpet. See Fig 2-Fig 3 . Go to next step.
On all models, disconnect oxygen sensor connector to be tested. Measure resistance between terminals B+ and HT at oxygen sensor connector. See Fig 4. Replace oxygen sensor if resistance is not 11-16 ohms.

Fig 1: Locating Heated Oxygen Sensors (GS300 & IS300)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Testing Oxygen Sensors (Bank 1, Sensor 1 & Bank 2, Sensor 1 - SC430)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 3: Testing Oxygen Sensors (Bank 1, Sensor 2 & Bank 2, Sensor 2 - SC430)

Fig 4: Testing Oxygen Sensor Heater