Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Oxygen sensor heater control
circuit... / Inspection procedure
Toyota Corolla (E120): Inspection procedure
Hint
:
- if different dtcs related to different systems that have terminal e2 as the ground terminal are output simultaneously, terminal e2 may be open.
- Read freeze frame data using the hand-held tester or the obd ii scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was lean or rich, etc. At the time of the malfunction.
1 Inspect heated oxygen sensor(heater resistance)
- Disconnect the h5 or h8 heated oxygen sensor connector.
- measure the resistance between the terminals of the heated oxygen sensor connector.

Standard:

- Reconnect the heated oxygen sensor connector.


2 Inspect efi relay
- Remove the efi relay from the engine room r/b.
- check for continuity in the efi relay.

Standard:

- Reinstall the efi relay.


3 Inspect ecm(ht1a or ht1b voltage)
- Turn the ignition switch on.
- measure the voltage between the applicable terminals of the e4 and e5 ecm connectors.

Standard:



4 Check harness and connector(heated oxygen sensor – ecm, heated oxygen sensor – efi relay)
- Check the harness and connector between the ecm and heated oxygen sensor connectors.
- Disconnect the h5 or h8 heated oxygen sensor connector.
- Disconnect the e4 or e5 ecm connector.
- Check the resistance between the wire harness side connectors.

Standard (check for open):

Standard (check for short):


- Reconnect the heated oxygen sensor connector.
- Reconnect the ecm connector.
- check the harness and connector between the heated oxygen sensor connector and efi relay.
- Disconnect the h5 or h8 heated oxygen sensor connector.
- Remove the efi relay from the engine room r/b.
- Check the resistance between the wire harness side connectors.

Standard (check for open):

Standard (check for short):

- Reconnect the heated oxygen sensor connector.
- Reinstall the efi relay.


Replace ecm
Other materials:
Battery
Check the battery as follows.
■ Battery exterior
Make sure that the battery terminals
are not corroded and that
there are no loose connections,
cracks, or loose clamps.
Terminals
Hold-down clamp
■Before recharging
When recharging, the battery produces
hydrogen gas which is flammable
and exp ...
Outside rear view mirrors
The rear view mirror's position
can be adjusted to
enable sufficient confirmation
of the rear view.
■When using the outside rear
view mirrors in a cold weather
When it is cold and the outside rear
view mirrors are frozen, it may not
be possible to fold/extend them or
adjust the mirror surface. Rem ...
Sun visors
To set the visor in the forward
position, flip it down.
To set the visor in the side
position, flip down, unhook,
and swing it to the side.
To use the side extender,
place the visor in the side
position, then slide it backward.
(if equipped)
Vanity mirrors
Slide the cover to open.
The v ...


