Toyota Corolla Repair Manual: 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 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:
Inspection procedure
Hint:
perform the troubleshooting of dtc p0335 first. If no trouble is
found, troubleshoot the engine mechanical
systems.
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 tr ...
Replacement
Hint: components:
1. Precaution
2. Disconnect battery negative terminal
3. Remove front door scuff plate rh
4. Remove rear door scuff plate rh
5. Remove front door opening trim rh
6. Remove rear door opening trim rh
7. Remove lap belt outer anchor cover
8. Remove center pillar garnis ...
Dtc check/clear
1. Dtc check (normal mode)
Notice:
hand–held tester only:
when the diagnostic system is switched from the normal
mode to the check mode, all the dtcs and freeze frame
data recorded in the normal mode will be erased. So before
switching modes, always check the dtcs and freeze frame
data, and n ...