Toyota Corolla Repair Manual: Circuit description
Refer to dtc p0120
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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 valve is closed at 0 km/h |
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Monitor description
The throttle position sensor varies its resistance with the angle of the throttle valve. The ecm applies a regulated reference voltage to the throttle position sensor “+” terminal and calculates the angle of the throttle valve based on the voltage present at the throttle position sensor “signal” terminal.
When the throttle valve is near the fully closed position, the output voltage of the throttle position sensor is low. When it is near the fully open position, the output voltage is high.
The ecm checks the indicated angle of the throttle valve during “stop and go” conditions. If the indicated angle (or voltage) in the “closed throttle” position is out of the specified range, the ecm interprets this as a malfunction in the throttle position sensor and sets a dtc.
Monitor strategy
Typical enabling condition
”Stop and go” is defined as follows: ”stop” indicates a vehicle speed of 0 mph (0 km/h). ”Go” indicates a vehicle speed of 18.6 Mph (30 km/h).
Typical malfunction thresholds
Component operating range
Throttle/pedal position
sensor/switch ”a” circuit
range/performance problem
Dtc p0121 throttle/pedal position
sensor/switch ”a” circuit
range/performance problem
Hint:
this is the purpose of the ”throttle position sensor”. ...
Inspection procedure
Hint:
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
usefu ...
Other materials:
Front differential oil seal
Replacement
1. Drain manual transaxle oil
torque: 39.2 Nvm (400 Kgf·cm, 29 ft·lbf)
2. Remove front wheels
3. Remove engine under cover lh
4. Remove engine under cover rh
5. Drain transaxle oil
6. Remove front drive shaft assy lh
sst 09520–01010, 09520–24010 (09520–32040)
7. Remove fr ...
Inspection procedure
1 Check source voltage
Measure the voltage of the battery.
Ok:
voltage: 10 – 14 v
2 Check air bag sensor assy center
Disconnect the negative (–) terminal cable from the battery, and wait at
least for 90 seconds.
disconnect the connectors from the airbag sensor assy cent ...
Overhaul
1. Remove manual transmission filler plug
Remove the manual transmission filler plug and gasket
from the manual transmission case.
2. Remove drain (mtm) plug sub–assy
Remove the drain (mtm) plug sub–assy and gasket from
the manual transmission case.
3. Remove speedometer se ...