Toyota ZZT230 series Repair Manual page 249

P0120
DTC
CIRCUIT DESCRIPTION
Throttle
Senso
Position
VTA
or (b)
DTC No.
Condition (a)
P01.20
HINT:
After confirming DTC P0120, use the
valve opening percentage.
Throllla valve opening position
Throttle
valve fully closed
0 %
Throttle Position Sensor/Switch
Circuit Malfunction
The throttle position sensor is mounted in the throttle body and
detects the throttle valve opening angle. When the throttle valve
Is fully closed, a voltage of approximately 0.3 -0.8 V Is applied
ECM to terminal VTA of the ECM. The voltage applied to the termi­
nals VTA of the ECM Increases In proporti o n to the opening
angle of the throttle valve and becomes approximately 3.2-4.9
V when the throttle valve is fully opened. The ECM judges the
vehicle driving conditions from this signal input from terminal
E2
VTA, and uses it as one of the conditions for deciding the air­
fuel ratio correction, power increase correction and fuek:ut
control etc.
Gondition
OTC Detecting with
continues more than 5 sec.:
II scan tool or TOYOTA hand-held tester to confirm the throttle
080
as
expressed percentage
Throttle valve fully open
ENGINE
•Open or short in throttle
• Throttle position sensor
•ECM
0 %
-
" "
A
Trouble Area
circuit
position sensor
Trouble Area
VC line open
VTA line open or short
E211ne open