Inspection Procedure

1. Allow the engine to idle.
2. Check for exhaust gas leak around the HO2S.

OK: 

No leak from the HO2S. 

NG: REPAIR LEAK 

OK: Go to Next Step 

Fig 1: Fuel-Trim And Rear HO2S Voltage Cross-Reference Chart

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1. Warm up the engine.
2. Allow the engine to idle.
3. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
4. Check the O2S B1 S2 (O2S B2 S2) values when the Control the Injection Volume for A/F Sensor is -12.5% (Lean fuel-trim).
5. Check the O2S B1 S2 (O2S B2 S2) values when the Control the Injection Volume for A/F Sensor is 25% (Rich fuel-trim).

Standard 

NG: REPLACE HEATED OXYGEN SENSOR 

OK: Go to Next Step 

1. Clear DTC (see DTC CHECK/CLEAR ).
2. Turn the engine switch Off.
3. Disconnect the battery negative terminal and wait for 1 minute.
4. Connect the battery negative terminal.
5. Start the engine.
   Fig 2: Engine Coolant Temperature - Driving Pattern

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. Perform the drive pattern.
   1. Warm up the engine.
   2. Accelerate the vehicle until 50 mph (80 km/h) and stop the vehicle.
   3. Drive the vehicle by 35 to 50 mph (60 to 80 km/h) for 5 minutes or more.
7. Check DTC.

OK: 

P0606 is not present. 

NG: REPLACE ECM 

OK: CHECK FOR INTERMITTENT PROBLEMS