Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Readiness monitor drive pattern / Oxygen sensor monitor (front and rear o2s system)
Toyota Corolla (E120): Oxygen sensor monitor (front and rear o2s system)

- Preconditions
The monitor will not run unless:
- mil is off
- drive pattern
- connect the obd ii scan tool to the dlc3 to check monitor status and preconditions.
- Start the engine and allow it to idle for 2 minutes or more.
- Drive the vehicle at 25 mph (40 km/h) or more for at least 50 seconds.
- Stop the vehicle and allow the engine to idle for 40 seconds or more.
- Perform steps (3) and (4) ten times.
- If the readiness status dose not switch to complete, make sure that the preconditions are met and the ignition switch is turned off and then repeat steps (1) through (5).
Other materials:
Circuit description
The variable valve timing (vvt) system includes the ecm, the oil control
valve (ocv) and the vvt controller.
The ecm sends a target ”duty–cycle” control signal to the ocv. This control
signal, applied to the ocv,
regulates the oil pressure supplied to the vvt controller. Camshaft timin ...
Circuit description
If the engine coolant temperature (ect) does not reach 75°c (167°f) despite
sufficient warm – up time has
elapsed.
Dtc no
Dtc detection condition
Trouble area
P0128
Condition (a), (b) and (c):
cold start
after engine is warmed up
& ...
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs adjustment
or repair. Contact your Toyota dealer as soon as possible.
Visible symptoms
● Fluid leaks under the vehicle.
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or u ...


