Inspection Procedure

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

   OK: 

   No leak from the HO2S. 

NG: REPAIR LEAK 

OK: Go to next step 

Fig 1: Identifying Fuel-Trim & Rear HO2S Voltage Cross Reference Graph

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

1. Warm up the engine.
2. Allow the engine to idle.
3. Select the tester menus: ENHANCED OBD-II, ACTIVE TEST AND A/F CONTROL.
4. Check the O2S B1S2 (O2S B2S2) values when the A/F CONTROL is -12.5% (Lean fuel-trim).
5. Check the O2S B1S2 (O2S B2S2) values when the A/F CONTROL is 25% (Rich fuel-trim).

   Standard 

   A/F CONTROL
   
   

   A/F CONTROL	O2S B1S2 (O2S B2S2)
   -12.5%	Less than 0.2 V
   25%	More than 0.8 V

NG: REPLACE HEATED OXYGEN SENSOR 

OK: Go to next step 

1. Clear DTC.
2. Turn the ignition switch OFF.
3. Disconnect the cable from the negative battery terminal and wait for 1 minute.
4. Connect the cable to the negative battery terminal.
5. Start the engine.
   Fig 2: Identifying Monitor Drive Pattern For P0606

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

   OK: 

   P0606 is not present. 

NG: REPLACE ECM 

OK: INTERMITTENT PROBLEMS