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
|
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) :
|
|
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:
Inspection procedure
1 Check door lock
2 Check wire harness (tvip ecu door lock)
Disconnect the tvip ecu and door lock connectors.
check the continuity between the terminals of the tvip
ecu and door lock connectors, as shown in the illustration
and table.
Standard:
3 Check wire harness ...
Circuit description
The actuator motor is operated by signals from the cruise control ecu assy.
Acceleration and deceleration
signals are transmitted by changes in the duty ratio (see below).
Duty ratio:
the duty ratio is the ratio of the period of continuity in one cycle. For
example, if a is the period of co ...
Checking the engine coolant
The coolant level is satisfactory
if it is between the "MAX" and
"MIN" lines on the reservoir
when the engine is cold.
Reservoir
"MAX" line
"MIN" line
If the level is on or below the "MIN"
line, add coolant up to the "MAX"
line.
■Coolant selection
Only use "Toyota Super Long Life
Coolant" or ...


