P2128
P2128 Acceleration Position Sensor 2 Circuit High Input
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
This DTC is set if the signal voltage of acceleration position sensor 2 is higher than threshold value.
DTC Detecting Condition
Specification
Schematic Diagram
Signal Waveform
Fig1) The given signal waveform is the normal waveform of Acceleration Position Sensor 1 (APS1) and Acceleration Position Sensor 2 (APS2) during acceleration and deceleration. Generally during acceleration, the signal of APS1 or APS2 increases; On the contrary, during deceleration, that of APS1 or APS2 decreases.
Fig2) The given data is the signal waveform of APS and idle switch when stepping on the accelerator pedal.
Terminal and 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
1) Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
NO
1) Go to "Signal Circuit Inspection" procedure.
Signal Circuit Inspection
Check for Short to Battery in Harness
1. Ignition "OFF"
2. Disconnect APS connector and ETS unit connector.
3. Ignition "ON" & Engine "OFF".
4. Measure voltage between terminal "3" of APS harness connector and chassis ground.
A. Specification Approx.0V
5. Is the voltage within specification?
YES
1) Go to "Ground Circuit Inspection" procedure.
NO
1) Check for short to battery in signal harness, Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
Ground Circuit inspection
Check for Open in Harness
1. Ignition "OFF".
2. Disconnect APS connector and PCM connector.
3. Measure resistance between terminal "1" of APS harness connector and "B17" of PCM harness connector.
A. Specification: Approx. 0 ohm
4. Is the resistance within specifications?
YES
1) Go to "Component Inspection" procedure.
NO
1) Check for open in ground harness, Repair as necessary and then go to "Verification of vehicle Repair" procedure.
Component Inspection
Check APS
1. Ignition "OFF".
2. Disconnect APS connector.
3. Measure resistance between terminal "1" and "2" of APS
4. Monitor the signal output of APS2 during stepping on the accelerator pedal slowly.
A. Specification
1) Approx. 0.3 ~ 1.0V (when not stepping on the accelerator pedal)
2) Approx. 4.0 ~ 5.5V (when stepping on the accelerator pedal fully)
5. Is the resistance or the signal voltage within specifications?
YES
1) Substitute with a known-good ETS unit or PCM and check for proper operation. If the problem is corrected,replace ETS unit or PCM and then go to "Verification of Vehicle Repair" procedure.
NO
1) 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.
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 DTC.
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
1) Go to the applicable troubleshooting procedure.
NO
1) System is performing to specification at this time.