4.
Read "DTC Status" parameter.
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 PCM 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 PCM determines operating conditions such as idle (closed throttle), part load, acceleration/deceleration, and wide-open throttle from the TPS. Also The PCM uses the Mass Air Flow Sensor (MAFS) signal along with the TPS signal to adjust fuel injection duration and ignition timing.
PCM sets DTC P0123 if the PCM detects signal voltage higher than the possible range of a properly operating TPS.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Voltage range check | ● Open in signal or ground circuit. ● Short to battery in signal circuit. ● Contact resistance in connectors. ● Faulty TP sensor. |
Enable Conditions | ● 6 ≤ Battery voltage ≤ 16V | |
Threshold value | ● Voltage ＞ 4.86 V | |
Diagonostic Time | ● 1 sec. | |
Fall Safe | ● Throttle position value is determined by function of engine speed, mass air flow and idle duty. |
TPS | Fully Closed | Fully Open | |
Throttle Angle (°) | 0~0.5° | 86° | |
Signal Voltage (V) | 0.2~0.8V | 4.3~4.8V | |
Resistance(kΩ) | Terminal 1 and 2 | 0.71 ~ 1.38kΩ at all temperature | 2.7kΩ at all temperature |
Terminal 2 and 3 | 1.6 ~ 2.4 ㏀ at all throttle position | ||
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
Press F4(DTAL) to select DTC information from the DTCs menu.
Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.
Read "DTC Status" parameter.
Is parameter displayed "History(Not Present) fault"?
History (Not Present) fault : DTC occurred but has been cleared.
Present fault : DTC is occurring at present time.
▶ Fault is intermittent caused by poor contact in the sensor's and/or the PCM's connector, which was repaired but PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
▶ Go to next step as below.
Many malfunctions in the electrical system are caused by poor harness(es) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
▶ Go to "Ground Circuit Inspection" procedure.
Ignition "OFF".
Disconnect TPS connector.
Ignition "ON" & Engine "OFF".
Measure voltage between terminal 2 of the sensor harness connector and chassis ground.
Specification : Approx. 0V
Is voltage within the specification?
▶ Go to step "Signal Circuit Inspection" procedure.
▶ Check the ground circuit for an open.
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
With connector still disconnected, measure voltage between terminal 1 of the sensor harness connector and chassis ground.
Specification : Approx. 5V
Is voltage within the specification?
▶ Go to "Component Inspection" procedure.
▶ Possibility of open or short to power in signal circuit. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Ignition "OFF" .
Disconnect TPS connector.
Measure resistance between terminals 2 and 3 of the sensor connector(Component side).
Specification : Approx. 1.6 ~ 2.4 kΩ at all throttle position
With still TPS connector disconnected, measure resistance between terminals 1 and 2 of the sensor connector(Component side).
Operate the throttle valve slowly from the idle position to the full open position and check the resistance changes smoothly in proportion with the throttle valve opening angle.
Specification : 0.71 ~ 1.38kΩ at closed throttle valve, 2.7kΩ at wide open throttle
Is resistance within the specification?
Check for poor connection between PCM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Check TPS for contamination, deterioration, or damage. Substitute with a known-good TPS and check for proper operation. If the problem is corrected, replace TPS and then go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode
Press F4(DTAL) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
Read "DTC Status" parameter
Is parameter displayed "History(Not Present) fault"?
▶ System performing to specification at this time. Clear the DTC
▶ Go to the applicable troubleshooting procedure.
