The Electronic Throttle Control(ETC) system which is composed of throttle body, Throttle Position Sensor(TPS)1&2 and Accelerator Position Sensor(APS) 1&2 controls the mass of airflow by driver's intention. The throttle valve opening is control by throttle motor which is controlled by ECM/PCM. TPS is a variable resistance and its value is cahnged by open angle of throttle valve.
ECM/PCM sends DTC P0121 if the difference between the throttle valve position value calculated by TPS1and the designated value by ECM/PCM is over certain value when the TPS2 is abnormal.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Plausibility check between | 1. Poor connection 2. TPS 3. ECM/PCM |
Enable Conditions |
•
IG "ON" | |
Threshold Value |
•
| TPS1 position - TPS2 position | > 6.3% | |
Diagnostic Time |
•
0.14sec | |
MIL ON Condition |
•
1 driving cycle |
Fig 1) Normal waveform of TPS1 & TPS2 with no accel padal depressed under IG ON condition
