P2138
DTC P2138 THROTTLE/PEDAL POSITION SENSOR/SWITCH "D" / "E" VOLTAGE CORRELATIONComponent 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. TPS 1 & 2 are sharing the same source voltage and ground.The throttle valve opening is control by throttle motor which is controlled by Engine Control Module (ECM).The opposite position indicator shows inverted signal characteristics.TPS 1 output voltage increases smoothly in proportion with the throttle valve opening angle after starting. TPS 2 output voltage decreases in inverse proportion with the throttle valve opening angle after starting. TPS provides feedback to the ECM to control the throttle motor in order to control the throttle valve opening angle properly in response to the driving condition.
DTC DESCRIPTION
Checking output signals from APS 1 and 2, under detecting condition, if output signals difference between APS 1 and 2 are detected more than 4.5% for the specified number of times., PCM sets P2138 and then MIL (Malfunction Indication Lamp) turns on.
DTC Detecting Condition:
Specification:
Schematic Diagram:
Signal Waveform And Data:
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 F4 (DTAL) 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, 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 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 "Power Circuit Inspection "procedure.
POWER CIRCUIT INSPECTION
1. IG "OFF"
2. Disconnect APS connector.
3. IG "ON" & ENG "OFF".
4. Measure voltage between terminal 1 of APS harness connector and chassis ground.
5. Measure voltage between terminal 4 of APS harness connector and chassis ground.
Specification : Approx. 5 V
6. Is the measured voltage within specification?
YES - Go to "Signal Circuit Inspection" procedure.
NO - Repair or replace as necessary and then, go to "Signal Circuit Inspection" procedure.
SIGNAL CIRCUIT INSPECTION
1. IG "OFF".
2. Disconnect APS and PCM connector.
3. Measure resistance between terminal 3 and 2 of APS harness connector.
Specification : Infinite
4. Is the measured resistance within specification?
YES - Go to "Component Inspection" procedure.
NO - Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure
COMPONENT INSPECTION
Specification:
1. Check APS
1. IG "ON" & ENG "OFF".
2. Measure signal waveform of APS 1 and APS 2 by stepping on and off with scantool
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.
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 to reuse the PCM on the others
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. 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.