Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit

Engine Hybrid System. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25
1Gr-Fe Engine Control. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25

DESCRIPTION

MONITOR DESCRIPTION

CONFIRMATION DRIVING PATTERN

FAIL-SAFE

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (ACCELERATOR POSITION SENSOR)

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

CHECK ECM (VCPA AND VCP2 VOLTAGE)

REPLACE ACCELERATOR PEDAL ROD ASSEMBLY

CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL POSITION 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:
This ETCS (Electronic Throttle Control System) does not use a throttle cable.
The accelerator pedal position sensor is mounted on the accelerator pedal rod assembly 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 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.

Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.1Gr-Fe Engine Control.Sfi System. Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit


DTC Code
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 position sensor (built into accelerator pedal rod assembly)
  2. ECM
P2122
VPA is 0.2 V or less for 0.5 seconds or more when the accelerator pedal is fully released (1 trip detection logic).
  1. Accelerator pedal position sensor (built into accelerator pedal rod assembly)
  2. Open in VCPA 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 position sensor (built into accelerator pedal rod 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 position sensor (built into accelerator pedal rod assembly)
  2. ECM
P2127
VPA2 is 0.5 V or less for 0.5 seconds or more when the accelerator pedal is fully released (1 trip detection logic).
  1. Accelerator pedal position sensor (built into accelerator pedal rod assembly)
  2. Open in VCP2 circuit
  3. Open or ground short in VPA2 circuit
  4. ECM
P2128
Conditions (a) and (b) continue for 2.0 seconds or more (1 trip detection logic):
(a) VPA2 is 4.8 V or higher.
(b) VPA is between 0.2 V and 3.45 V.
  1. Accelerator pedal position sensor (built into accelerator pedal rod assembly)
  2. Open in EPA2 circuit
  3. ECM
P2138
Condition (a) or (b) 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 0.2 V or less and VPA2 is 0.5 V or less.
  1. Short between VPA and VPA2 circuits
  2. Accelerator pedal position sensor (built into accelerator pedal rod assembly)
  3. ECM

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

Trouble Area
Accelerator Position No. 1
When Accelerator Pedal Released
Accelerator Position No. 2
When Accelerator Pedal Released
Accelerator Position No. 1
When Accelerator Pedal Depressed
Accelerator Position No. 2
When Accelerator Pedal 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 4.9 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
EPA circuit open
4.5 to 4.9 V
4.5 to 4.9 V
4.5 to 4.9 V
4.5 to 4.9 V
Normal condition
0.5 to 1.1 V
1.2 to 2.0 V
2.6 to 4.5 V
3.4 to 4.9 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 below 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 0.2 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.

CONFIRMATION DRIVING PATTERN


Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.1Gr-Fe Engine Control.Sfi System. Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit

  1. Connect the intelligent tester to the DLC3.
  2. Turn the ignition switch to ON and turn the tester on.
  3. Clear the 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 tester 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 / DTC [C].
  9. Read the 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.

    Tester 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.

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 to be driven. 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


Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.1Gr-Fe Engine Control.Sfi System. Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit


INSPECTION PROCEDURE

HINT:
  1. These DTCs relate to the accelerator pedal position sensor.
  2. Read freeze frame data using the intelligent tester. 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.
1.READ VALUE USING INTELLIGENT TESTER (ACCELERATOR POSITION SENSOR)


    Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.1Gr-Fe Engine Control.Sfi System. Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit

  1. Connect the intelligent tester to the DLC3.

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

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

  1. Read the value displayed on the tester.

    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 4.9 V
    Text in Illustration
    *a
    		Depressed
    *b
    		Released


NG
Go to step 2
OK

CHECK FOR INTERMITTENT PROBLEMS (HILUX_TGN26 RM000000PDQ0YKX.html)

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

  1. Disconnect the accelerator pedal rod 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
    G6-6 (VPA) - G155-18 (VPA)
    		Always
    		Below 1 Ω
    G6-5 (EPA) - G155-20 (EPA)
    		Always
    		Below 1 Ω
    G6-4 (VCPA) - G155-26 (VCPA)
    		Always
    		Below 1 Ω
    G6-3 (VPA2) - G155-19 (VPA2)
    		Always
    		Below 1 Ω
    G6-2 (EPA2) - G155-21 (EPA2)
    		Always
    		Below 1 Ω
    G6-1 (VCP2) - G155-27 (VCP2)
    		Always
    		Below 1 Ω
    G6-6 (VPA) or G155-18 (VPA) - Body ground
    		Always
    		10 kΩ or higher
    G6-5 (EPA) or G155-20 (EPA) - Body ground
    		Always
    		10 kΩ or higher
    G6-4 (VCPA) or G155-26 (VCPA) - Body ground
    		Always
    		10 kΩ or higher
    G6-3 (VPA2) or G155-19 (VPA2) - Body ground
    		Always
    		10 kΩ or higher
    G6-2 (EPA2) or G155-21 (EPA2) - Body ground
    		Always
    		10 kΩ or higher
    G6-1 (VCP2) or G155-27 (VCP2) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK ECM (VCPA AND VCP2 VOLTAGE)
Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.1Gr-Fe Engine Control.Sfi System. Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit

  1. Disconnect the accelerator pedal rod assembly connector.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    G6-4 (VCPA) - G6-5 (EPA)
    		Ignition switch ON
    		4.5 to 5.5 V
    G6-1 (VCP2) - G6-2 (EPA2)
    		Ignition switch ON
    		4.5 to 5.5 V
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Accelerator Pedal Rod Assembly)


NG
REPLACE ECM (HILUX_TGN26 RM000000VW202SX.html)
OK


4.REPLACE ACCELERATOR PEDAL ROD ASSEMBLY

  1. Replace the accelerator pedal rod assembly (HILUX_TGN26 RM000000VWD02BX.html).


NEXT


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

  1. Connect the intelligent tester to the DLC3.

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

  1. Clear the DTCs (HILUX_TGN26 RM000000PDK12JX.html).

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

  1. Turn the ignition switch to 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 / DTC.

  1. Read the DTCs.

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


B
END
A

REPLACE ECM (HILUX_TGN26 RM000000VW202SX.html)