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:
Inspection procedure
Hint:
if dtc p0441 (purge flow), p0446 (vsv for ccv or vsv for pressure
switching valve), p0451, p0452
or p0453 is output with dtc p0442 or p0456 , first troubleshoot
dtc p0441, p0446, p0451, p0452 or p0453. If no malfunction is detected,
troubleshoot dtc
p0442 or p0456 next.
...
Overhaul
1. Precaution
2. Disconnect battery negative terminal
3. Inspect place front wheels facing straight ahead
4. Remove horn button assy
Notice:
if the airbag connector is disconnected with the ignition
switch being at on, dtcs will be recorded.
using a torx socket wrench, loosen the ...
Replacement
1. Remove proportioning valve assy
Using sst, disconnect the 5 brake tubes from the proportioning
valve assy.
Sst 09023–00100
Remove the 2 bolts and proportioning valve assy from the
body.
2. Install proportioning valve assy
Install the proportioning valve assy w ...


