P2123
2AZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2120, P2122, P2123, P2125, P2127, P2128, P2138: Throttle / Pedal Position Sensor / Switch "D" Circuit
DESCRIPTION
HINT
- This ETCS (Electronic Throttle Control System) does not use a throttle cable.
- These DTCs relate to the Accelerator Pedal Position (APP) sensor.
The Accelerator Pedal Position (APP) sensor is mounted on the accelerator pedal bracket and has 2 sensor circuits: VPA (main) and VPA2 (sub). This sensor is a non-contact type and uses Hall-effect elements in order to yield accurate signals even in extreme driving conditions, such as at high speeds as well as very low speeds. The voltage, which is applied to terminals VPA and VPA2 of the ECM, varies between 0.5 V and 4.5 V in proportion to the operating angle of the accelerator pedal (throttle valve). A signal from VPA indicates the actual accelerator pedal opening angle (throttle valve opening angle) and is used for engine control. A signal from VPA2 conveys the status of the VPA circuit and is used to check the APP sensor itself.
The ECM monitors the actual accelerator pedal opening angle (throttle valve opening angle) through the signals from VPA and VPA2, and controls the throttle actuator according to these signals.
HINT
When any of these DTCs are stored, check the APP sensor voltage by entering the following menus on the Techstream: Powertrain / Engine and ECT / Data List / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.
MONITOR DESCRIPTION
When either output voltage of VPA or VPA2 deviates from the standard range, or the difference between the output voltages of the 2 sensor circuits is less than the threshold, the ECM determines that there is a malfunction in the APP sensor. The ECM then illuminates the MIL and stores a DTC.
Example:
When the output voltage of VPA drops below 0.4 V for more than 0.5 seconds when the accelerator pedal is fully depressed, DTC P2122 is stored.
If the malfunction is not repaired successfully, a DTC is stored 2 seconds after the engine is next started.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
P2120:
P2122:
P2123:
P2125:
P2127:
P2128:
P2138:
COMPONENT OPERATING RANGE
CONFIRMATION DRIVING PATTERN
1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON and turn the Techstream on.
3. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
4. Turn the ignition switch off and wait for at least 30 seconds.
5. Turn the ignition switch to ON and turn the Techstream on [A].
6. Fully depress and release the accelerator pedal [B].
7. Check that 5 seconds or more have elapsed since the ignition switch was turned to ON.
8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].
9. Read pending DTCs.
HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
11. Input the DTC: P2120, P2122, P2123, P2125, P2127, P2128 or P2138.
12. Check the DTC judgment result.
HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [B] through [C] again.
13. If no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.
HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.
FAIL-SAFE
When any of DTCs P2120, P2121, P2122, P2123, P2125, P2127, P2128 and P2138 are stored, the ECM enters fail-safe mode. If either of the 2 sensor circuits malfunctions, the ECM uses the remaining circuit to calculate the accelerator pedal position to allow the vehicle to continue driving. If both of the circuits malfunction, the ECM regards the accelerator pedal as being released. As a result, the throttle valve is closed and the engine idles.
Fail-safe mode continues until a pass condition is detected, and the ignition switch is turned off.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT
Read freeze frame data using the Techstream. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
1. READ VALUE USING TECHSTREAM (ACCELERATOR POSITION SENSOR)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.
(e) Read the value displayed on the Techstream.
Standard Voltage:
Text in Illustration
NG -- CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR - ECM)
OK -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems
2. CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR - ECM)
(a) Disconnect the accelerator pedal position sensor connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Standard Resistance (Check for Short):
(d) Reconnect the accelerator pedal position sensor connector.
(e) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK ECM (VCPA AND VCP2 VOLTAGE)
(a) Disconnect the accelerator pedal position sensor connector.
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Text in Illustration
(d) Reconnect the accelerator pedal position sensor connector.
NG -- REPLACE ECM Removal
OK -- Continue to next step.
4. REPLACE ACCELERATOR PEDAL ROD ASSEMBLY
(a) Replace the accelerator pedal rod assembly Removal.
NEXT -- Continue to next step.
5. CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL POSITION SENSOR DTCS)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Clear DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Start the engine.
(f) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
(g) Read DTCs.
Result
B -- END
A -- REPLACE ECM Removal