The Throttle Position Sensor (TPS) is mounted on the throttle body and detects the opening angle of the throttle plate.The TPS has a variable resistor (potentiometer) whose characteristic is the resistance changing according to the throttle angle. During acceleration, the TPS resistance between the reference 5V and the signal terminal decreases and output voltage increases; during deceleration, the TPS resistance increases and TPS output voltage decreases.The ECM supplies a reference 5V to the TPS and the output voltage increases directly with the opening of the throttle valve. The TPS output voltage will vary from 0.2~0.8V at closed throttle to 4.3~4.8V at wide-open throttle.The ECM determines operating conditions such as idle (closed throttle), part load, acceleration/deceleration, and wide-open throttle from the TPS. Also The ECM uses the Mass Air Flow Sensor (MAFS) or Manifold Absolute Pressure Sensor (MAPS) signal along with the TPS signal to adjust fuel injection duration and ignition timing.
If the sensor input voltage is higher than the maximum threshold value during 0.5 sec under normal driving condition, ECM sets DTC P0123.
Item
Detecting Condition
Possible Cause
DTC Strategy
Signal check, high
Poor connection
Open or short to power in signal circuit
Open in ground circuit
TPS
Enable Conditions
Engine speed > 440 rpm
Threshold Value
Calculated signal from sensor voltage > 95.7%
Diagnostic Time
0.5 sec
MIL ON Condition
3 driving cycle
Specification
Coil Resistance (O)
1.6 ~ 2.4 [20 ? 68 ?]
Check whether the TPS signals increase at the same time when accelerating. During acceleration, the TPS output voltage increases; during deceleration, the TPS output voltage decreases.