Checking output signals from TPS under detecting condition, if the difference between real and target throttle position is above the specified value, ECM/PCM sets P0638.
Item | Detecting Condition | Possible Cause | |
DTC Strategy | Case 1 |
•
Return Spring Check | 1. Throttle stuck 2. Open in motor circuit 3. Faulty motor 4. Faulty ECM/PCM |
Case 2 |
•
Abnormal value of TPS re-adaptation | ||
Case 3 |
•
TPS re-adaptation was failed due to violated input conditions | ||
Case 4 |
•
TPS adaptation fault or abnormal value during the first initialization | ||
Case 5 |
•
Limp-home position check | ||
Enable Conditions | Case 1 |
•
During TPS adaptation | |
Case 2 |
•
During TPS adaptation (Throttle is made to approach the lower mech. throttle limit stop via ramp)
•
Learned value already saved
•
During TPS adaptation | ||
Case 3 |
•
During TPS adaptation
•
During TPS adaptation | ||
Case 4 |
•
First initialization
•
IG ON | ||
Case 5 |
•
IG ON | ||
Threshold Value | Case 1 |
•
Throttle position > Limp-home pos.+3% | |
Case 2 |
•
Voltage throttle poti 1 at the lower limit stop is lower than 0.305V or Voltage throttle poti 2 at the lower limit stop is higher than 4.695V or Voltage Sum of throttle poti1 and 2 is lower than 0V or higher than 5V
•
Voltage throttle poti 1 at the lower limit stop + offset is higher than 0.695V
•
Voltage throttle poti 2 at the lower limit stop - offset is lower than 4.305V ※ Offset = 0.025V | ||
Case 3 |
•
Engine speed is higher than 250rpm
•
Vehicle speed is higher than 0kph
•
Accel. Pedal is higher than 14.9%
•
ECT is lower than 5.3℃ or higher than 100.5℃
•
IAT is lower than 5.3℃
•
Voltage is lower than 10V | ||
Case 4 |
•
Learning stop due to violated input condition and UMA learning error | ||
Case 5 |
•
Limp-home position is higher than 19.5% or lower than 1.0% | ||
Diagnosis Time | Case 1 |
•
0.56 sec. | |
Case 2 |
•
0.3 sec. | ||
Case 3 |
•
Immediate | ||
Case 4 |
•
Immediate | ||
Case 5 |
•
Immediate | ||
MIL On Condition | Case 1 |
•
1 Driving Cycle | |
Case 2 |
•
1 Driving Cycle | ||
Case 3 |
•
2 Driving Cycle
•
1 Driving Cycle | ||
Case 4 |
•
1 Driving Cycle | ||
Case 5 |
•
2 Driving Cycle | ||
