Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Oxygen sensor circuit slow
response / Circuit description
Toyota Corolla (E120): Circuit description
Refer to dtc p0130
|
Dtc no. |
Dtc detection condition |
Trouble area |
| P0133 | After engine has been warmed up, if response time that heated
oxygen sensor’s output voltage reaches from rich to lean. Or from lean to rich, is 0.6 Second or more during idling. (2 Trip detection logic) |
|
| If response time of heated oxygen sensor’s output voltage in one rich–lean cycle is 6 seconds or more during idling. (2 Trip detection logic) |
Hint
: sensor 1 refers to the sensor closest to the engine assembly.
Monitor description
The engine control module (ecm) uses the heated oxygen sensor information to regulate the air–fuel ratio close to a stoichiometric ratio. This maximizes the catalytic converter’s ability to purify the exhaust gases.
The sensor detects oxygen levels in the exhaust gas and sends this signal to the ecm.
The inner surface of the sensor element is exposed to the outside air. The outer surface of the sensor element is exposed to the exhaust gas. The sensor element is made of the platinum coated zirconia and includes an integrated heating element. The heated oxygen sensor has the characteristic whereby its output voltage change suddenly in the vicinity of the stoichiometric air–fuel ratio. The heated oxygen sensor generates waveform of a voltage between 0 v and 1 v in response to the oxygen concentration in exhaust gas.
When the output voltage of the heated oxygen sensor is 0.55 V or more, the ecm judges that the air–fuel ratio is rich. When it is 0.40 V or less, the ecm judges that the air–fuel ratio is lean.
The ecm monitors the response feature of the heated oxygen sensor. If the response time of the sensor output status change from rich to lean or vice versa becomes longer, the ecm interprets this as a malfunction in the heated oxygen sensor and sets a dtc.
Monitor strategy
Typical enabling condition
Typical malfunction thresholds
Component operating range
Wiring diagram
Refer to dtc p0130
Other materials:
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Check and replace ecu
Notice:
start an inspection of the connector from the backside
of the connector on the wire harness side with
the connector connected to the ecu.
When no measurement condition is specified, perform
the inspection with the engine stopped and also
the ignition switch on.
First check the ec ...
Circuit description
The variable valve timing (vvt) system includes the ecm, the oil control
valve (ocv) and the vvt controller.
The ecm sends a target ”duty–cycle” control signal to the ocv. This control
signal, applied to the ocv,
regulates the oil pressure supplied to the vvt controller. Camshaft timin ...