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(PCM). 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 PCM to control the throttle motor in order to control the throttle valve opening angle properly in response to the driving condition.
The DTC P0221 is set when the intake manifold model filtered reduced area controller is out of range in low or high load.
Item
Detecting Condition
Possible Cause
DTC Strategy
Plausibility check between TPS1 and TPS2
Faulty TPS2
Poor connection or damaged harness
Enable Conditions
No engine stop and engine start
No TPS adaptation request
No relevant failure
Threshold Value
An absolute value of TPS2 - TPS1 > 7.6%
Diagnostic Time
0.3sec.
MIL On Condition
1 Drive Cycle
Limp-Home
Forced limited power mode : When the DTC is set, the PCM reduces engine torque by 25% of normal value.
The PCM uses TPS1 signal to monitor the controlled opening angle of the throttle valve.