Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Oxygen sensor circuit no activity
detected / Circuit description
Toyota Corolla (E120): Circuit description
Refer to dtc p0130
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Dtc no. |
Dtc detecting condition |
Trouble area |
| P0134 | After engine is warmed up, heated oxygen sensor (bank 1
sensor 1) output does not indicate rich (greater than 0.45 V)
even once when conditions (a), (b), (c), (d) and (e) continue for
more than 65 seconds (1 trip detection logic) :
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Hint
: after confirming dtc p0134, check the output voltage of the heated oxygen sensor (bank 1 sensor 1) in the ”diagnosis / enhanced obd ii / data list / all” using the hand-held tester or the obd ii scan tool.
If the output voltage of the heated oxygen sensor is always less than 0.1 V, the sensor circuit may be open or short.
Monitor description
The ecm uses the heated oxygen sensor to optimize the air–fuel mixture in the closed–loop fuel control.
This control helps decrease exhaust emissions by providing the catalyst with a nearly stoichiometric mixture.
The sensor detects the oxygen level in the exhaust gas and the ecm uses this data to control the air–fuel ratio. The sensor output voltage ranges from 0 v to 1 v. If the signal voltage is less than 0.4 V, the air–fuel ratio is lean. If the signal voltage is more than 0.5 V, the air–fuel ratio is rich. If the sensor does not indicate rich even once despite the conditions for the closed–loop fuel control being met and a specified time period has passed, the ecm will conclude that the closed–loop fuel control is malfunctioning. The ecm will illuminate the mil and a dtc is set.
Monitor strategy

Typical enabling condition

Typical malfunction thresholds

Component operating range

Wiring diagram
Refer to dtc p0130
Other materials:
Seat belt warning lamp for driver’s seat does not
operate
Wiring diagram
Inspection procedure
1 Check combination meter assy
Ground terminal c9–12 on the combination meter side.
check that the warning lightlights up.
Ok: warning light lights up.
2 Inspect front seat inner belt assy lh
Disconnect the front seat inner belt ...
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:
installation is in the reverse order of the removal. But the installation is
indicated only when it has a point.
1. Remove radiator grille sub–assy
Remove the 2 bolts and clip.
using a screwdriver, remove the radiator grille.
Hint:
tape the screwdriver tip before use. ...


