DTC    P2120    Throttle / Pedal Position Sensor / Switch "D" Circuit

DTC    P2122    Throttle / Pedal Position Sensor / Switch "D" Circuit Low Input

DTC    P2123    Throttle / Pedal Position Sensor / Switch "D" Circuit High Input

DTC    P2125    Throttle / Pedal Position Sensor / Switch "E" Circuit

DTC    P2127    Throttle / Pedal Position Sensor / Switch "E" Circuit Low Input

DTC    P2128    Throttle / Pedal Position Sensor / Switch "E" Circuit High Input

DTC    P2138    Throttle / Pedal Position Sensor / Switch "D" / "E" Voltage Correlation

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DESCRIPTION

HINT:
  1. These DTCs relate to the Accelerator Pedal Position (APP) sensor.
  2. 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. It 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.

A112620E04


DTC No.
DTC Detection Condition
Trouble Area
P2120
VPA fluctuates rapidly beyond upper and lower malfunction thresholds for 0.5 seconds or more
(1 trip detection logic)
  1. Accelerator pedal position sensor (accelerator pedal assembly)
  2. ECM
P2122
VPA 0.4 V or less for 0.5 seconds or more when accelerator pedal depressed
(1 trip detection logic)
  1. Accelerator pedal position sensor (accelerator pedal assembly)
  2. Open in VCPA circuit
  3. Open or ground short in VPA circuit
  4. ECM
P2123
VPA 4.8 V or more for 2.0 seconds or more
(1 trip detection logic)
  1. Accelerator pedal position sensor (accelerator pedal assembly)
  2. Open in EPA circuit
  3. ECM
P2125
VPA2 fluctuates rapidly beyond upper and lower malfunction thresholds for 0.5 seconds or more
(1 trip detection logic)
  1. Accelerator pedal position sensor (accelerator pedal assembly)
  2. ECM
P2127
VPA2 1.2 V or less for 0.5 seconds or more when accelerator pedal depressed
(1 trip detection logic)
  1. Accelerator pedal position sensor (accelerator pedal assembly)
  2. Open in VCP2 circuit
  3. Open or ground short in VPA2 circuit
  4. ECM
P2128
Following conditions (a) and (b) met for 2.0 seconds or more
(1 trip detection logic):
(a) VPA2 4.8 V or more
(b) VPA between 0.4 V and 3.45 V
  1. Accelerator pedal position sensor (accelerator pedal assembly)
  2. Open in EPA2 circuit
  3. ECM
P2138
Either of following conditions (a) or (b) met for 2.0 seconds or more
(1 trip detection logic):
(a) Difference between VPA and VPA2 0.02 V or less
(b) VPA 0.4 V or less and VPA2 1.2 V or less
  1. Short between VPA and VPA2 circuits
  2. Accelerator pedal position sensor (accelerator pedal assembly)
  3. ECM

HINT:
When any of these DTCs are set, check the accelerator pedal position sensor voltage by entering the following menus: Powertrain / Engine and ECT / Data List / Accelerator Position No. 1 and Accelerator Position No. 2.

Trouble Area
Accelerator Position No. 1
When AP Released
Accelerator Position No. 2
When AP Released
Accelerator Position No. 1
When AP Depressed
Accelerator Position No. 2
When AP Depressed
VCP circuit open
0 to 0.2 V
0 to 0.2 V
0 to 0.2 V
0 to 0.2 V
Open or ground short in VPA circuit
0 to 0.2 V
1.2 to 2.0 V
0 to 0.2 V
3.4 to 5.0 V
Open or ground short in VPA2 circuit
0.5 to 1.1 V
0 to 0.2 V
2.5 to 4.5 V
0 to 0.2 V
EPA circuit open
4.5 to 5.0 V
4.5 to 5.0 V
4.5 to 5.0 V
4.5 to 5.0 V
Normal condition
0.5 to 1.1 V
1.2 to 2.0 V
2.5 to 4.5 V
3.4 to 5.0 V

HINT:
AP denotes Accelerator Pedal.


FAIL-SAFE

The APP sensor has two (main and sub) sensor circuits. If a malfunction occurs in either of the sensor circuits, the ECM detects the abnormal signal voltage difference between the two sensor circuits and switches to fail-safe mode. In fail-safe mode, the functioning circuit is used to calculate the accelerator pedal opening angle to allow the vehicle to continue driving. If both circuits malfunction, the ECM regards the opening angle of the accelerator pedal as being fully closed. In this case, the throttle valve remains closed as if the engine is idling. If a pass condition is detected and then the ignition switch is turned off, the fail-safe operation stops and the system returns to a normal condition.

WIRING DIAGRAM


A159167E11


INSPECTION PROCEDURE

HINT:
Read freeze frame data using an intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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.

1.READ VALUE USING INTELLIGENT TESTER (ACCELERATOR POSITION NO. 1 AND ACCELERATOR POSITION NO. 2)


    FI07052E18

  1. Connect an intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

  1. Enter the following menus: Powertrain / Engine and ECT / Data List / Accelerator Position No. 1 and Accelerator Position No. 2.

  1. Read the value.

    Standard Voltage:
    Accelerator Pedal Operation
    		Accelerator Position No. 1
    		Accelerator Position No. 2
    Released
    		0.5 to 1.1 V
    		1.2 to 2.0 V
    Depressed
    		2.5 to 4.5 V
    		3.4 to 5.0 V



NG
Go to step 2
OK

CHECK FOR INTERMITTENT PROBLEMS (Click here)  

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

  1. Disconnect the accelerator pedal position sensor connector.

  1. Disconnect the ECM connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    A33-6 (VPA) - A18-55 (VPA)
    		Always
    		Below 1 Ω
    A33-5 (EPA) - A18-59 (EPA)
    		Always
    		Below 1 Ω
    A33-4 (VCPA) - A18-57 (VCPA)
    		Always
    		Below 1 Ω
    A33-3 (VPA2) - A18-56 (VPA2)
    		Always
    		Below 1 Ω
    A33-2 (EPA2) - A18-60 (EPA2)
    		Always
    		Below 1 Ω
    A33-1 (VCP2) - A18-58 (VCP2)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    A33-6 (VPA) or A18-55 (VPA) - Body ground
    		Always
    		10 kΩ or higher
    A33-5 (EPA) or A18-59 (EPA) - Body ground
    		Always
    		10 kΩ or higher
    A33-4 (VCPA) or A18-57 (VCPA) - Body ground
    		Always
    		10 kΩ or higher
    A33-3 (VPA2) or A18-56 (VPA2) - Body ground
    		Always
    		10 kΩ or higher
    A33-2 (EPA2) or A18-60 (EPA2) - Body ground
    		Always
    		10 kΩ or higher
    A33-1 (VCP2) or A18-58 (VCP2) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the accelerator pedal position sensor connector.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.INSPECT ECM (VCPA AND VCP2 VOLTAGE)


    A200914E01

  1. Disconnect the accelerator pedal position sensor connector.

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A33-4 (VCPA) - A33-5 (EPA)
    		Ignition switch ON
    		4.5 to 5.5 V
    A33-1 (VCP2) - A33-2 (EPA2)
    		Ignition switch ON
    		4.5 to 5.5 V

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Accelerator Pedal Position Sensor)

  1. Reconnect the accelerator pedal position sensor connector.



NG
REPLACE ECM (Click here)
OK


4.REPLACE ACCELERATOR PEDAL ASSEMBLY

  1. Replace the accelerator pedal assembly (Click here).


NEXT


5.CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL POSITION SENSOR DTC)

  1. Connect an intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

  1. Clear the DTCs (Click here).

  1. Allow the engine to idle for 15 seconds or more.

  1. Fully depress and release the accelerator pedal several times quickly.

  1. Enter the following menus: Powertrain / Engine and ECT / DTC.

  1. Read DTCs.
    Result 
    Result
    		Proceed to
    DTC P2120, P2122, P2123, P2125, P2127, P2128, and/or P2138 are output
    		A
    DTC is not output
    		B



B
END
A

REPLACE ECM (Click here)