2010 > G 1.4 DOHC > Engine > Unleaded EOBD > P0122 Throttle/Pedal Position Sensor/Switch A Circuit Low Input

Component Location

General Description

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.

DTC Description

If the sensor input voltage is lower than the minimum threshold value during 0.08 sec under normal driving condition, PCM sets DTC P0122.

DTC Detecting Condition

Item
Detecting Condition
Possible Cause

DTC Strategy
● Signal check, low
● Poor connection
● Open or short to ground in power circuit
● Short to ground in signal circuit
● TPS
● ECM

Enable Conditions
● Engine speed > 600 rpm

Threshold Value
● Calculated signal from sensor voltage < 3.1%

Diagnostic Time
● 0.08 sec

MIL ON Condition
● 2 driving cycle

Specification

ITEM
Specification

TPS Resistance (kΩ)
2kΩ ± 20% (20°C)

Schematic Diagram

Signal Waveform

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