P0123
DTC P0123 THROTTLE/PEDAL POSITION SENSOR/SWITCH "A" CIRCUIT HIGH INPUTComponent Location:
COMPONENT LOCATION
GENERAL DESCRIPTION
The ETSCM (Electronic Throttle System Control Module) is integrated with PCM(Powertrain Control Module). Therefore, Make sure that location of ETS Module is changed. Differently from the conventional throttle control system whose throttle angle is controlled by the accelerator cable connected to throttle blade from accelerator pedal,Electronic Throttle System(ETS) is the throttle body whose throttle angle is controlled by control module. It consists of ETS-motor.Accelerator Position Sensor(APS),Throttle Position Sensor(TPS) and Limp home valve. Engine PCM takes APS signal as input signal instead of TPS signal and calculates the optimum throttle angle and outputs opening signal to ETS-motor. TPS monitors a real opening angle of throttle valve and this information is sent to PCM. TPS1 is main signal and used for controlling engine in calculating the target opening angle of throttle and for determining whether TPS2 is normally working. TPS2 is sub-signal which is used when TPS1 is malfunctioning and used for determining whether TPS1 is normally working.
DTC DESCRIPTION
This DTC is set if the output voltage of TPS 2 is higher than the threshold value.
DTC Detecting Condition:
DTC DETECTING CONDITION
Specification:
SPECIFICATION
Schematic Diagram:
SCHEMATIC DIAGRAM
Signal Waveform & Data:
SIGNAL WAVEFORM & DATA
MONITOR SCANTOOL DATA
1. Install Scantool and monitor the "TPS 2(Sub) or TP Sensor(ECM)" parameter on scantool.
Test Condition : Ignition "ON" & Engine "OFF"
Specification :
Throttle valve fully closed : approx. 4.5 - 5.0 V
Throttle valve fully open : approx. 0.3- 0.9 V
TPS signal should decrease smoothly as throttle is opened.
2. Is the TPS signal within specifications?
YES: Fault is intermittent caused by poor contact in the sensor's and/or PCM' s connector or was repaired and 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.
NO: Go to "W/Harness Inspection" procedure.
TERMINAL & CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness and terminals.
Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES: Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO: Go to "Signal Circuit Inspection" procedure.
SIGNAL CIRCUIT INSPECTION
1. Check for short to battery in harness
1. Ignition "OFF"
2. Disconnect TPS connector.
3. Ignition "ON" & Engine "OFF"
4. Measure voltage between terminal "4" of the TPS harness connector and chassis ground.
Specification : Approx. 0 V
5. Is the measured voltage within specifications?
YES: Go to "Check for open in harness" as below
NO:
- Check for short to battery in signal harness.
- Repair or replace as necessary go to " Verification of Vehicle Repair" procedure.
2. Check for open in harness
1. Ignition "OFF".
2. Disconnect TPS connector and PCM connector.
3. Measure resistance between terminal "4" of the TPS harness connector and "C8" of the PCM harness connector.
Specification : Approx. Below 1 Ohm
4. Is the measured resistance within specifications?
YES: Go to "Ground Circuit Inspection" procedure.
NO: Check for open in signal harness. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
GROUND CIRCUIT INSPECTION
1. Check for open in harness
1. Ignition "OFF"
2. Disconnect TPS connector.
3. Measure resistance between terminal "3" of the TPS harness connector and chassis ground.
Specification : Approx. Below 1 Ohm
4. Is the measured resistance within specifications?
YES: Go to "Component Inspection" procedure.
NO: Check for open in harness. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
COMPONENT INSPECTION
1. Check TPS resistance
1. Disconnect TPS connector and measure resistance between terminals 1 and 3 of the TPS connector.
Specification : Approx. 3.5 - 6.5 kOhm ( with throttle valve fully closed) at 20 °C(68 °F)
2. With still TPS connector disconnected, measure resistance between terminals 3 and 4 of the TPS2 connector.
3. Operate the throttle valve slowly from the idle position to the full open position and verify that the TPS2's resistance changes smoothly in inverse proportion with the throttle valve opening angle.
Specification : TPS2's resistance changes smoothly in inverse proportion with the throttle valve opening angle.
4. Is the measured resistance within specification ?
YES: Go to "Check PCM" as below.
NO: Substitute with a known - good TPS and check for proper operation. If the problem is corrected, replace TPS and go to "Verification of Vehicle Repair" procedure.
2. Check PCM
1. Ignition "OFF"
2. Connect Scantool and Disconnect TPS connector
3. Ignition "ON" & Select simulation function on scantool.
4. Simulate voltage at terminal "4" of TPS 2 signal connector.
5. Is the TPS signal value changed according to simulation voltage?
YES: Fault is intermittent caused by poor contact in the sensor's and/or PCM's connector. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification vehicle Repair" procedure.
NO: Substitute with a known - good PCM and check for proper operation.
If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.
NOTE:
Procedure of ETS Initialization
1. Erase the trouble codes on PCM
2. Turn the ignition key on less than 1 second and turn it off(Do not start the engine)
3. Turn the ignition key off and keep this condition until the main relay is turned off.(It will takes 10 second)
4. Turn ignition key on more than 1 second to record the throttle motor position on the EEPROM
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs.
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions.
4. Monitor that all readiness test have been verified as "Complete"
5. Are any DTCs present ?
YES: Go to the applicable troubleshooting procedure.
NO: System is performing to specification at this time.