P2123
P2123Component Location:
General Description
The 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 ECM judges the current opening angle of the accelerator pedal from APS1&2, and the ECM 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. And then MIL(Malfunction Indication Lamp) turns on.
DTC Detecting condition:
Specification:
Signal Waveform:
Schematic Diagram:
Monitor DTC Status
1. Check DTC Status
1. Connect scantool to Data Link Connector(DLC).
2. IG "ON".
3. Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F5(INFO) to check DTC's information from the DTCs menu
4. Read "DTC Status" parameter.
5. Is parameter displayed "Present fault"?
YES
a. Go to "Terminal and Connector inspection" procedure.
NO
a. 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, ending, 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 "Signal Circuit Inspection" procedure.
Signal Circuit Inspection
1. Check short to battery in harness
1. IG "OFF".
2. Disconnect APS and PCM connector.
3. Measure resistance between terminal 1 and 2 of APS harness connector.
4. Measure resistance between terminal 2 and 4 of APS harness connector.
Specification : Infinite
5. 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
1. Check open in harness
1. IG "OFF".
2. Disconnect APS connector.
3. Measure voltage between terminal 4 of APS harness connector and chassis ground.(Fig. A)
4. Measure voltage between terminal 4 and 5 of APS harness connector.(Fig. B)
Specification : Fig. "A" - Fig. "B" = approx. 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".
2. Measure signal waveform of APS by pressing and depressing accelerator pedal.
Specification :
3. Is the measured signal waveform O.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.
CAUTION: There is a memory reset function on scantool that can erase optional components automatically detected and memorized by PCM. Before or after testing PCM on the vehicle, use this function to reuse 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 scan tool and select "Diagnostic Trouble Codes(DTCs)" mode
2. Press F5(INFO) and confirm that "DTC Readiness Flag" indicates "Complete". 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.