The Electronic Throttle Control(ETC) system is made of the components throttle body, Throttle Position Sensor(TPS)1&2 and Accelerator Position Sensor(APS) 1&2. TPS1&2 are sharing the same source voltage and ground.The throttle valve opening is control by throttle motor which is controlled by Engine Control Module(ECM).The opposite position indicator shows inverted signal characteristics.TPS1 output voltage increases smoothly in proportion with the throttle valve opening angle after starting. TPS2 output voltage decreases in inverse proportion with the throttle valve opening angle after starting. TPS provides feedback to the ECM to control the throttle motor in order to control the throttle valve opening angle properly in response to the driving condition.
Checking output signals from TPS 1 and 2 under detecting condition, if output signals difference between TPS1 and TPS2 are detected more than 8% for the specified number of times., ECM sets P0221.
Item
Detecting Condition
Possible Cause
DTC Strategy
Determines if TPS#1 disagrees with TPS#2
Poor Connection
Open or short in TPS circuit
Faulty TPS
Faulty ECM
Enable Conditions
Ignition "ON"
Threshold value
Difference between average values of TPS1 and TPS2 > 8%
Diagnosis Time
Continuous
MIL On Condition
1 Driving Cycles
Throttle Opening (°)
Output Voltage (V) [Vref=5.0]
TPS1
TPS2
0°
0.0V
5.0V
10°
0.5V
4.5V
20°
0.9V
4.1V
30°
1.4V
3.6V
40°
1.8V
3.2V
50°
2.3V
2.7V
60°
70°
80°
90°
100°
110°
Fig.1) Normal waveform of TPS1 & TPS2 with no accel padal depressed under IG ON condition
Fig.2) Normal waveform of TPS1 & TPS2 with accel padal depressed under IG ON condition
Fig.3) Normal data of TPS1 & TPS2 under IG ON condition
Fig.4) Normal data of TPS1 & TPS2 under open condition
Fig.5) Normal data of TPS1 & TPS2 under short to ground in TSP1 circuit