P2123
DTC P2123 THROTTLE / PEDAL POSITION SENSOR / SWITCH "D" CIRCUIT HIGH INPUTComponent Location:
GENERAL DESCRIPTION
Electronic Throttle Control(ETC) system is made of the components throttle body, Throttle Position Sensor(TPS) 1 & 2 and Accelerator Position Sensor(APS) 1 & 2. The APS is mounted in the accelerator pedal to detect the opening angle of the accelerator pedal. It has 2 sensors to detect the accelerator position and a malfunction of the accelerator position sensor. The PCM judges the current opening angle of the accelerator pedal from APS 1 & 2, and the PCM controls the throttle motor based on these signals.
DTC DESCRIPTION
Checking output signals from APS 1, under detecting condition, if output signals are above the threshold, PCM sets P2123. MIL(Malfunction Indication Lamp) turns on.
DTC Detecting Condition:
Specification:
Schematic Diagram:
Signal Waveform And Data:
SIGNAL WAVEFORM AND DATA
Fig.1. This is a signal waveform of APS 1 & 2 which shows that APS 2 increases voltage just half of APS 1 voltage increase when accelerating.
MONITOR DTC STATUS
1. Check DTC Status
1. Connect scantool to Data Link Connector(DLC).
2. IG "ON".
3. Select "DTC" button, and then Press "DTC Status" to check DTC's information from the DTCs menu.
4. Read "DTC Status" parameter.
5. Is parameter displayed "Present fault"?
YES - Go to "Terminal and connector inspection" procedure.
NO - 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.
TERMINAL AND CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness and terminal condition. 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 " Power Circuit Inspection " procedure.
SIGNAL CIRCUIT INSPECTION
- CHECK SHORT TO BATTERY IN HARNESS
1. IG "OFF" and disconnect APS connector and PCM connector.
2. Measure resistance between APS1 signal and APS1 power terminals of APS harness connector.
3. Measure resistance between APS1 signal and APS2 power terminals of APS harness connector.
Specification : Infinite
4. Is the measured resistance within specification?
YES - Go to "Ground Circuit Inspection" procedure.
NO - Repair or replace as necessary and then, go to"Verification of Vehicle Repair" procedure.
GROUND CIRCUIT INSPECTION
- CHECK OPEN IN HARNESS
1. IG "OFF" and disconnect APS connector.
2. IG "ON" and ENG "OFF"
3. Measure voltage between APS1 power terminal of APS harness connector and chassis ground.(Measurement "A")
4. Measure voltage between APS1 power and APS1 ground terminals of APS harness connector.(Measurement "B")
Specification : Voltage difference between measurement "A" and "8"is below 200 mV.
5. Is the measured voltage within specification?
YES - Go to "Component Inspection" procedure.
NO - Repair or replace contact resistance or open in harness and then, go to "Verification of Vehicle Repair" procedure.
COMPONENT INSPECTION
1. Check APS
1. Ignition "ON" & ENG "OFF".
Specification:
2. Measure waveform of APS by pressing and depressing accelerator pedal with scantool.
3. Is the measured signal waveform 0.K?
YES - Substitute with a known-good PCM and check for proper operation. If the problem is corrected,replace PCM and then go to "Verification of Vehicle Repair" procedure.
NOTE: There is a memory reset function on scantool that can erase optional parts automatically detected and memorized by PCM. Before or after testing PCM on the vehicle, use this function before reusing the PCM
NO - 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. Connect scantool and select "DTC" button.
2. Press "DTC Status" button and confirm that "DTC Readiness Flag" indicates "Completed". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
3. Read "DTC Status" parameter
4. Is parameter displayed "History(Not Present) fault"?
YES - System performing to specification at this time. Clear the DTC
NO - Go to the applicable troubleshooting procedure.