Toyota Corolla (E120): 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 |
|
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
Other materials:
Inspection procedure
Hint:
hand–held tester only:
narrowing down the trouble area is possible by performing ”a/f control” active
test (heated oxygen
sensor or other trouble areas can be distinguished).
Perform active test using hand–held tester (a/f control).
Hint:
”a/f control” is the active te ...
Maintenance requirements
To ensure safe and economical driving, day-to-day care and regular maintenance
are essential. It is the owner’s responsibility to perform regular checks. Toyota
recommends the following maintenance:
General maintenance
General maintenance should be performed on a daily basis. This can be don ...
Overhaul
1. Remove w/head taper screw plug no.2
Using a socket hexagon wench 10, remove the taper
screw plug and gasket.
2. Remove valve lifter
Remove the valve lifters from the cylinder head.
3. Remove valve
Place the cylinder head on wooden blocks.
using sst, compres ...