P2123
P2122 Acceleration Position Sensor 1 Circuit Low Input
General Information
Component Location
General Description
The ETS(Electronic Throttle System) is the throttle body whose throttle angle is controlled by control module. It consists of ETS unit, ETS-motor, Accelerator Position Sensor(APS),Throttle Position Sensor(TPS) and Limp home valve. Among above-mentioned parts , APS consists of APS1, APS2 and idle switch which detects the closed throttle position. When a driver steps on the gas pedal, the output signal of APS1 is sent to ETS unit and that of APS2 is sent to the PCM. And then the PCM sends throttle valve target opening value to ETS unit after calculating from signals such as APS and other input values. The ETS unit controls ETS motor to meet PCM's throttle valve target opening value.
DTC Description
If the signal voltage of APS is higher than threshold value, this DTC is set.
DTC Detecting Condition
Schematic Diagram
Connector View
Signal Waveform
Monitor DTC Status
1. Connect scantool to Data Link Connector(DLC).
2. Warm up the engine to normal operating temperature.
3. Monitor the "TPS1", "TPS1","APS1" and "APS2" parameter on the scantool.
A. Specification :
Approx. 0.3~1.0V at idle & No load (TPS1 or TPS ETS)
Approx. 4.2~4.8V at idle & No load (TPS2 or TPS EMS)
Approx. 0.3~1.0V at idle & No load (APS1 or APS ETS)
Approx. 0.3~0.9V at idle & No load (APS2 or APS EMS)
4. Is Current data displayed correctly?
YES
- Fault is intermittent caused by poor contact in the related sensor's and/or ETS unit 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 then 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 APS connector.
(3) Ignition "ON" & Engine "OFF"
(4) Measure voltage between terminal "6" of APS harness connector and chassis ground.
A. Specification : Approx.0V
(5) Is the measured voltage within specifications?
YES
- Go to "Ground circuit inspection" procedure.
NO
- Check for short to battery in signal harness, Repair 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 APS connector and ETS unit connector.
(3) Measure resistance between terminal "7" of APS harness connector and "17" of ETS unit harness connector.
A. Specification: Approx. below 1 ohm
(4) Is the measured resistance within specifications?
YES
- Go to "Component inspection" procedure.
NO
- Check for open in ground harness, Repair replace as necessary and then go to "Verification of vehicle Repair" procedure.
Component Inspection
1. Check APS
(1) Connect APS and PCM connector.
(2) Ignition "ON" & Engine "OFF"
(3)Monitor APS 1 and APS 2 signal waveform when stepping on accelerator pedal.
A. Specification:
Approx. 0.3 ~ 1.0V (when not stepping on the accelerator pedal)
Approx. 4.0 ~ 5.5V (when stepping on the accelerator pedal fully)
(4) Is the signal waveform within specifications?
YES
- Substitute with a known-good ETS unit and check for proper operation. If the problem is corrected,replace ETS unit and then go to "Verification of Vehicle Repair" procedure. If the ETS unit needs to be replaced, do initialization after it is replaced.
NO
- Check APS for contamination, deterioration, or damage. Substitute with a known-good APS and check for proper operation.If the problem is corrected, replace APS and then 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 seconds)
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.