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P2127





2GR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2120, P2122, P2123, P2125, P2127, P2128, P2138: Throttle / Pedal Position Sensor / Switch "D" Circuit


DESCRIPTION

This ETCS (Electronic Throttle Control System) does not use a throttle cable.

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 V and 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 set, check the APP sensor voltage by selecting the following menu items on the Techstream: Powertrain / Engine / Data List / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.





HINT
- Accelerator pedal positions are expressed as voltages.
- AP stands for Accelerator Pedal.

MONITOR DESCRIPTION

- When either of the output voltages 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 sets 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 set.

- If the malfunction is not repaired successfully, a DTC is set 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 engine switch on (IG) and turn the Techstream on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

4. Turn the engine switch off and wait for 30 seconds.

5. Turn the engine switch on (IG) 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 DTCs were cleared.

8. Enter the following menus: Powertrain / Engine / Trouble Codes.

9. Read the DTC [C].

HINT
- If a DTC is output, the system is malfunctioning.
- If a DTC is not output, perform the following procedure.

10. Enter the following menus: Powertrain / Engine / 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 NORMAL, the system is normal.
- If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [B] through [C] again.

13. If no 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 or P2138 is 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.

The ECM continues operating in fail-safe mode until a pass condition is detected, and the engine switch is then turned off.

WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
- Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction Freeze Frame Data.
- These DTCs relate to the Accelerator Pedal Position (APP) sensor.

PROCEDURE

1. READ VALUE USING TECHSTREAM (ACCEL SENSOR OUT NO. 1 AND ACCEL SENSOR OUT NO. 2)

(a) Connect the Techstream to the DLC3.





(b) Turn the engine switch on (IG) and turn the Techstream on.

(c) Enter the following menus: Powertrain / Engine / Data List / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.

(d) Read the value displayed on the Techstream.

Standard voltage:





OK -- CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL POSITION SENSOR DTCS)
NG -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR - ECM)

(a) Disconnect the A34 Accelerator Pedal Position (APP) sensor connector.

(b) Disconnect the A7 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):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. INSPECT ECM (VCPA AND VCP2 VOLTAGE)

(a) Disconnect the A34 APP sensor connector.





(b) Turn the engine switch on (IG).

(c) Measure the voltage according to the value(s) in the table below.

Standard voltage:





NG -- REPLACE ECM
OK -- Continue to next step.

4. REPLACE ACCELERATOR PEDAL ROD ASSEMBLY

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 engine switch on (IG) and turn the Techstream on.

(c) Clear DTCs Reading and Clearing Diagnostic Trouble Codes.

(d) Start the engine.

(e) Drive the vehicle in accordance with driving pattern described in the Confirmation Driving Pattern.

(f) Enter the following menus: Powertrain / Engine / Trouble Codes.

(g) Read DTCs.

Result:





B -- END

A -- REPLACE ECM
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