Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit

Engine Hybrid System. Yaris. Ncp93, 131
1Nz-Fe Engine Control. Yaris. Ncp93, 131

DESCRIPTION

MONITOR DESCRIPTION

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

CONFIRMATION DRIVING PATTERN

FAIL-SAFE

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING TECHSTREAM (ACCELERATOR PEDAL POSITION SENSOR)

CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL SENSOR ASSEMBLY - ECM)

INSPECT ECM (VCPA AND VCP2 VOLTAGE)

REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY

CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL SENSOR DTCS)

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


DESCRIPTION

HINT:
  1. This Electronic Throttle Control System (ETCS) does not use a throttle cable.
  2. These DTCs relate to the accelerator pedal position sensor.
The accelerator pedal position sensor is built into the accelerator pedal assembly and has 2 sensor circuits: VPA (main) and VPA2 (sub). This sensor is a non-contact type sensor 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 accelerator pedal position 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.

Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan). Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit


DTC No.
DTC Detection Condition
Trouble Area
P2120
VPA fluctuates rapidly beyond the upper and lower malfunction thresholds for 0.5 seconds or more (1 trip detection logic).
  1. Accelerator pedal sensor assembly
  2. ECM
P2122
VPA is 0.4 V or less for 0.5 seconds or more when the accelerator pedal is depressed (1 trip detection logic).
  1. Accelerator pedal sensor assembly
  2. Open in VCP1 circuit
  3. Open or ground short in VPA circuit
  4. ECM
P2123
VPA is 4.8 V or higher for 2.0 seconds or more (1 trip detection logic).
  1. Accelerator pedal sensor assembly
  2. Open in EPA circuit
  3. ECM
P2125
VPA2 fluctuates rapidly beyond the upper and lower malfunction thresholds for 0.5 seconds or more (1 trip detection logic).
  1. Accelerator pedal sensor assembly
  2. ECM
P2127
VPA2 is 1.2 V or less for 0.5 seconds or more when the accelerator pedal is depressed (1 trip detection logic).
  1. Accelerator pedal sensor assembly
  2. Open in VCP2 circuit
  3. Open or ground short in VPA2 circuit
  4. ECM
P2128
Both of the following conditions continue for 2.0 seconds or more (1 trip detection logic):
(a) VPA2 is 4.8 V or higher.
(b) VPA is between 0.4 V and 3.45 V.
  1. Accelerator pedal sensor assembly
  2. Open in EPA2 circuit
  3. ECM
P2138
Either of the following conditions continues for 2.0 seconds or more (1 trip detection logic):
(a) The difference between VPA and VPA2 is 0.02 V or less.
(b) VPA is 0.4 V or less and VPA2 is 1.2 V or less.
  1. Short between VPA and VPA2 circuits
  2. Accelerator pedal sensor assembly
  3. ECM

HINT:
When any of these DTCs are output, check the accelerator pedal position sensor voltage using the Techstream. Enter the following menus: Powertrain / Engine and ECT / Data List / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.

Trouble Area
Accelerator Pedal Released
Accelerator Pedal Depressed
Accel Sensor Out No. 1
Accel Sensor Out No. 2
Accel Sensor Out No. 1
Accel Sensor Out No. 2
Open in VCP circuit
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 4.7 V
Open or ground short in VPA2 circuit
0.5 to 1.1 V
0 to 0.2 V
2.6 to 4.5 V
0 to 0.2 V
Open in EPA circuit
4.5 to 4.98 V
4.5 to 4.98 V
4.5 to 4.98 V
4.5 to 4.98 V
Normal condition
0.5 to 1.1 V
1.2 to 2.0 V
2.6 to 4.5 V
3.4 to 4.7 V
HINT:
Accelerator pedal positions are expressed as voltages.

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 accelerator pedal position 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


Related DTCs
P2120: Accelerator Pedal Position Sensor 1 Range Check (Fluctuating)
P2122: Accelerator Pedal Position Sensor 1 Range Check (Low Voltage)
P2123: Accelerator Pedal Position Sensor 1 Range Check (High Voltage)
P2125: Accelerator Pedal Position Sensor 2 Range Check (Fluctuating)
P2127: Accelerator Pedal Position Sensor 2 Range Check (Low Voltage)
P2128: Accelerator Pedal Position Sensor 2 Range Check (High Voltage)
P2138: Accelerator Pedal Position Sensor Range Check (Correlation)
Required Sensors/Components (Main)
Accelerator pedal sensor assembly
Required Sensors/Components (Related)
-
Frequency of Operation
Continuous
Duration
0.5 seconds: P2120, P2122, P2125 and P2127
2.0 seconds: P2123, P2128 and P2138
MIL Operation
Immediate
Sequence of Operation
None

TYPICAL ENABLING CONDITIONS


Monitor runs whenever following DTCs not present
None
Either of following conditions met:
-
Ignition switch
ON (0.012 seconds or more)
Throttle actuator power
ON

TYPICAL MALFUNCTION THRESHOLDS


P2120:
Either of following conditions met:
1 or 2
1. All of following conditions met:
(a) and (b)
(a) VPA voltage
0.4 V or less
(b) VPA2 voltage - Learned VPA2 accelerator off position voltage
0.04 V or higher
2. VPA voltage
4.8 V or higher

P2122:
All of following conditions met:
(a) and (b)
(a) VPA voltage
0.4 V or less
(b) VPA2 voltage - Learned VPA2 accelerator off position voltage
0.04 V or higher

P2123:
VPA voltage
4.8 V or higher

P2125:
Either of following conditions met:
1 or 2
1. All of following conditions met:
(a) and (b)
(a) VPA2 voltage
1.2 V or less
(b) VPA voltage - Learned VPA accelerator off position voltage
0.04 V or higher
2. VPA2 voltage when VPA voltage 0.4 to 3.45 V
4.8 V or higher

P2127:
All of following conditions met:
(a) and (b)
(a) VPA2 voltage
1.2 V or less
(b) VPA voltage - Learned VPA accelerator off position voltage
0.04 V or higher

P2128:
VPA2 voltage when VPA voltage 0.4 to 3.45 V
4.8 V or higher

P2138:
Either of following conditions met:
Condition A or B
Condition A
-
Difference between VPA and VPA 2 voltages
0.02 V or less
Condition B
-
VPA voltage
0.4 V or less
VPA2 voltage
1.2 V or less

COMPONENT OPERATING RANGE


VPA voltage
0.4 to 4.8 V
VPA2 voltage
1.2 to 4.8 V
Difference between VPA and VPA2 voltages
Higher than 0.02 V

CONFIRMATION DRIVING PATTERN


Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan). Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit

  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 procedure).
  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 is turned ON.
  8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].
  9. Read pending DTCs.
    HINT:
    1. If a pending DTC is output, the system is malfunctioning.
    2. 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.

    Techstream Display
    		Description
    NORMAL
    1. DTC judgment completed
    2. System normal
    ABNORMAL
    1. DTC judgment completed
    2. System abnormal
    INCOMPLETE
    1. DTC judgment not completed
    2. Perform driving pattern after confirming DTC enabling conditions
    N/A
    1. Unable to perform DTC judgment
    2. Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
    HINT:
    1. If the judgment result shows NORMAL, the system is normal.
    2. If the judgment result shows ABNORMAL, the system has a malfunction.
    3. If the judgment result shows INCOMPLETE or N/A, perform steps [B] through [C] again.
  13. If no pending DTC is output, perform a universal trip and check for permanent DTCs (YARIS_NCP93 RM000000PDK0T5X.html).
    HINT:
    1. If a permanent DTC is output, the system is malfunctioning.
    2. 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 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.
Fail-safe mode continues until a pass condition is detected, and the ignition switch is turned off.

WIRING DIAGRAM


Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan). Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit


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 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 TECHSTREAM (ACCELERATOR PEDAL POSITION SENSOR)


    Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan). Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

  1. Read the value displayed on the Techstream.

    Standard Voltage:
    Accelerator Pedal Operation
    		Accel Sensor Out No. 1
    		Accel Sensor Out No. 2
    		Difference between Accel Sensor Out No. 1 and Accel Sensor Out No. 2
    Released
    		0.5 to 1.1 V
    		1.2 to 2.0 V
    		More than 0.02 V
    Depressed
    		2.6 to 4.5 V
    		3.4 to 4.7 V
    Text in Illustration
    *a
    		Depressed
    *b
    		Released


NG
Go to step 2
OK

CHECK FOR INTERMITTENT PROBLEMS (YARIS_NCP93 RM000000PDQ0Q2X.html)

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

  1. Disconnect the accelerator pedal sensor assembly connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    A64-6 (VPA) - A72-51 (VPA)
    		Always
    		Below 1 Ω
    A64-5 (EPA) - A72-52 (EPA)
    		Always
    		Below 1 Ω
    A64-4 (VCPA) - A72-53 (VCPA)
    		Always
    		Below 1 Ω
    A64-3 (VPA2) - A72-54 (VPA2)
    		Always
    		Below 1 Ω
    A64-2 (EPA2) - A72-55 (EPA2)
    		Always
    		Below 1 Ω
    A64-1 (VCP2) - A72-56 (VCP2)
    		Always
    		Below 1 Ω
    A64-6 (VPA) or A72-51 (VPA) - Body ground
    		Always
    		10 kΩ or higher
    A64-5 (EPA) or A72-52 (EPA) - Body ground
    		Always
    		10 kΩ or higher
    A64-4 (VCPA) or A72-53 (VCPA) - Body ground
    		Always
    		10 kΩ or higher
    A64-3 (VPA2) or A72-54 (VPA2) - Body ground
    		Always
    		10 kΩ or higher
    A64-2 (EPA2) or A72-55 (EPA2) - Body ground
    		Always
    		10 kΩ or higher
    A64-1 (VCP2) or A72-56 (VCP2) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.INSPECT ECM (VCPA AND VCP2 VOLTAGE)


    Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan). Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit

  1. Disconnect the accelerator pedal sensor assembly 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
    A64-4 (VCPA) - A64-5 (EPA)
    		Ignition switch ON
    		4.5 to 5.5 V
    A64-1 (VCP2) - A64-2 (EPA2)
    		Ignition switch ON
    		4.5 to 5.5 V
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Accelerator Pedal Sensor Assembly)


NG
REPLACE ECM (YARIS_NCP93 RM000001CN002IX.html)
OK


4.REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY

  1. Replace the accelerator pedal sensor assembly (YARIS_NCP93 RM000003VHW00JX.html).


NEXT


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

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

  1. Clear the DTCs (YARIS_NCP93 RM000000PDK0T5X.html).

  1. Turn the ignition switch off and wait for at least 30 seconds.

  1. Turn the ignition switch to ON and turn the Techstream on.

  1. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

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

  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 (YARIS_NCP93 RM000001CN002IX.html)