Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Mass or volume air flow circuit
range/performance problem / Circuit description
Toyota Corolla (E120): Circuit description
Refer to dtcs p0100
|
Dtc no. |
Dtc detection condition | Trouble area |
| P0101 | After engine is warmed up, conditions (a) to (d) continue for
more than 10 seconds (2 trip detection logic):
|
|
Conditions (a) and (b) continue for more than 6 seconds: (2 trip
detection logic)
|
Monitor description
The maf (mass air flow) sensor helps the ecm calculates the amount of air flowing through the throttle valve. The ecm uses this information to determine the fuel injection time and provides a proper air–fuel ratio.
Inside the maf sensor, there is a heated platinum wire exposed to the flow of intake air. By applying a specific current to the wire, the ecm heats this wire to a given temperature. The flow of incoming air cools the wire and an internal thermister, changing their resistance. To maintain a constant current value, the ecm varies the voltage applied to these components in the maf sensor. The voltage level is proportional to the air flow through the sensor and the ecm interprets this voltage as the intake air amount. If there is a defect in the sensor or an open or short circuit, the voltage level will deviate outside the normal operating range. The ecm interprets this deviation as a defect in the maf sensor and sets a dtc.
Example: if the voltage is more than 2.2 V at idle, or less than 0.4 V at idle off, the ecm interprets this as a defect in the maf sensor and sets a dtc.
Monitor strategy

Typical enabling conditions

Typical malfunction thresholds

Wiring diagram
Refer to dtc p0100
Other materials:
Inspection
1. Inspect outer mirror switch assy
Inspect the mirror switch continuity.
Left side for left/right adjustment switch:
inspect the mirror switch continuity
Standard (left side):
If the result is not as specified, replace the switch assembly.
Right side for left/r ...
Inspection procedure
1 Check p/t squib(rh) circuit(airbaga sensor assy center – front
seat outer belt assy rh)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connectors between the airbag sensor
assy center and the seat belt pretensi ...
Circuit description
Refer to dtc p0120
Dtc no.
Dtc detection condition
Trouble area
P0121
The following condition is met 4 times. After the vehicle speed
has exceeded 19 mph (30 km/h) once, the throttle position
sensor output value is out of normal range when the throttle
...


