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
When the ignition switch is turned on, battery positive voltage is applied to
the coilwhich closes the contacts
of the efi main relay (marked: efi) and supplies power to terminal +b of the ecm.
This signal causes current to flow to the coil, closing the contacts of the efi
relay and supplyin ...
Replacement
Hint: components:
1. Place front wheels facing straight ahead
2. Remove front wheels
3. Remove engine under cover lh
4. Remove engine under cover rh
5. Remove exhaust pipe
6. Drain transaxle oil
7. Remove hood sub–assy
8. Remove cylinder head cover no.2
9. Remove air cleaner assy
10. R ...
Source voltage drop
The srs is equipped with a voltage–increase circuit (dc–dc converter) in the
airbag sensor assy center
in case the source voltage drops.
When the battery voltage drops, the voltage–increase circuit (dc–dc converter)
functions to increase the
voltage of the srs to normal voltage.
...


