Conditioning For Sensor Testing

HINT:

Perform the operation with the engine speeds and time durations described below prior to checking the waveforms of the A/F and HO2 sensors. This is in order to activate the sensors sufficiently to obtain the appropriate inspection results.

Fig 1: Engine Speed Driving Pattern

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Connect Techstream to the DLC3.
2. Put the engine in inspection mode (See CHECK MODE PROCEDURE  ).
3. Start the engine and warm it up with all the accessories switched OFF, until the engine coolant temperature stabilizes.
4. Run the engine at engine speed of between 2,500 rpm for at least 3 minutes.
5. While running the engine at 2,500 rpm for 2 seconds and 1,500 rpm for 2 seconds, check the waveforms of the A/F and HO2 sensors using the tester or scan tool.

Case	A/F Sensor (Sensor 1) Output Voltage	HO2 Sensor (Sensor 2) Output Voltage	Main Suspected Trouble Area
1	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	-
2	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	A/F sensor A/F sensor heater A/F sensor circuit
3	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	HO2 sensor HO2 sensor heater HO2 sensor circuit
4	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Fuel pressure Gas leakage from exhaust system (Air-fuel ratio extremely lean or rich)

• Following the Control the Injection Volume for A/F Sensor procedure enables technicians to check and graph the output voltages of both the A/F and HO2 sensors.
• To display the graph, enter the following menus on the tester: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / A/F Control System / AFS B1 S1 or AFS B2 S1 and O2S B1 S2 or O2S B2 S2 then press the graph button on the Data List view.