Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit

Land Cruiser URJ200 URJ202 GRJ200 VDJ200 - 1GR-FE ENGINE CONTROL

DESCRIPTION

MONITOR DESCRIPTION

FAIL-SAFE

WIRING DIAGRAM

INSPECTION PROCEDURE

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

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

CHECK ECM (VCPA AND VCP2 VOLTAGE)

REPLACE ACCELERATOR PEDAL SENSOR 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 sensor 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 amount the accelerator pedal is depressed (throttle valve opening angle). The signal from VPA indicates the actual accelerator pedal position (throttle valve opening angle) and is used for engine control. The 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 position (throttle valve opening angle) through the signals from VPA and VPA2, and controls the throttle actuator according to these signals.

Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit. 1GR-FE ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

DTC No.DTC Detection ConditionTrouble Area
P2120VPA fluctuates rapidly beyond the upper and lower malfunction thresholds for 0.5 seconds or more (1 trip detection logic).
Accelerator pedal sensor assembly
ECM
P2122VPA is 0.4 V or less for 0.5 seconds or more when the accelerator pedal is fully released (1 trip detection logic).
Accelerator pedal sensor assembly
Open in VCPA circuit
Open or short to ground in VPA circuit
ECM
P2123VPA is 4.8 V or higher for 2.0 seconds or more (1 trip detection logic).
Accelerator pedal sensor assembly
Open in EPA circuit
ECM
P2125VPA2 fluctuates rapidly beyond the upper and lower malfunction thresholds for 0.5 seconds or more (1 trip detection logic).
Accelerator pedal sensor assembly
ECM
P2127VPA2 is 1.2 V or less for 0.5 seconds or more when the accelerator pedal is fully released (1 trip detection logic).
Accelerator pedal sensor assembly
Open in VCP2 circuit
Open or short to ground in VPA2 circuit
ECM
P2128Conditions (a) and (b) are met 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.
Accelerator pedal sensor assembly
Open in EPA2 circuit
ECM
P2138Condition (a) or (b) is met for 2.0 seconds or more (1 trip detection logic):
(a) 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.
Short between VPA and VPA2 circuits
Accelerator pedal sensor assembly
ECM
  • HINT:
  • When any of these DTCs is output, check the accelerator pedal position sensor voltage by entering the following menus: Powertrain / Engine and ECT / Data List / Accel Sensor Out No.1 and Accel Sensor Out No.2.
Trouble AreaAccel Sensor Out No.1
When Accelerator Pedal Released		Accel Sensor Out No.2
When Accelerator Pedal Released		Accel Sensor Out No.1
When Accelerator Pedal Depressed		Accel Sensor Out No.2
When Accelerator Pedal Depressed
VCP circuit open0 to 0.2 V0 to 0.2 V0 to 0.2 V0 to 0.2 V
Open or short to ground in VPA circuit0 to 0.2 V1.2 to 2.0 V0 to 0.2 V3.4 to 4.75 V
Open or short to ground in VPA2 circuit0.5 to 1.1 V0 to 0.2 V2.6 to 4.5 V0 to 0.2 V
EPA circuit open4.5 to 5.0 V 4.5 to 5.0 V4.5 to 5.0 V4.5 to 5.0 V
Normal0.5 to 1.1 V 1.2 to 2.0 V2.6 to 4.5 V3.4 to 4.75 V
  • HINT:
  • Accelerator pedal positions are expressed as voltages.

MONITOR DESCRIPTION

When the output voltage of either 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.


If the malfunction is not repaired successfully, the DTC is stored 2 seconds after the engine is next started.


FAIL-SAFE

When DTC 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 limits the engine output. 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

Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit. 1GR-FE ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

INSPECTION PROCEDURE

  • HINT:
These DTCs relate to the accelerator pedal position sensor.
Read freeze frame data using the GTS. 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 GTS (ACCEL SENSOR OUT NO.1 AND ACCEL SENSOR OUT NO.2)
Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit. 1GR-FE ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

Connect the GTS to the DLC3.

Turn the ignition switch to ON and turn the GTS on.

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

Read the value displayed on the GTS.

  • Standard Voltage:
  • Accelerator Pedal OperationAccel Sensor Out No. 1Accel Sensor Out No. 2Difference between Accel Sensor Out No. 1 and Accel Sensor Out No. 2
    Released0.5 to 1.1 V1.2 to 2.0 VMore than 0.02 V
    Depressed2.6 to 4.5 V3.4 to 4.75 V
Text in Illustration
*aDepressed
*bReleased
OK
Go to step 5
NG
Go to step 2
2.CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR - ECM)

Disconnect the accelerator pedal sensor assembly connector.

Disconnect the ECM connector.

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

  • Standard Resistance:
  • for LHD
    Tester ConnectionConditionSpecified Condition
    A31-6 (VPA) - A38-55 (VPA)AlwaysBelow 1 Ω
    A31-5 (EPA) - A38-58 (EPA)AlwaysBelow 1 Ω
    A31-4 (VCPA) - A38-57 (VCPA)AlwaysBelow 1 Ω
    A31-3 (VPA2) - A38-56 (VPA2)AlwaysBelow 1 Ω
    A31-2 (EPA2) - A38-60 (EPA2)AlwaysBelow 1 Ω
    A31-1 (VCP2) - A38-59 (VCP2)AlwaysBelow 1 Ω
    A31-6 (VPA) or A38-55 (VPA) - Body groundAlways10 kΩ or higher
    A31-5 (EPA) or A38-58 (EPA) - Body groundAlways10 kΩ or higher
    A31-4 (VCPA) or A38-57 (VCPA) - Body groundAlways10 kΩ or higher
    A31-3 (VPA2) or A38-56 (VPA2) - Body groundAlways10 kΩ or higher
    A31-2 (EPA2) or A38-60 (EPA2) - Body groundAlways10 kΩ or higher
    A31-1 (VCP2) or A38-59 (VCP2) - Body groundAlways10 kΩ or higher
  • for RHD
    Tester ConnectionConditionSpecified Condition
    A31-6 (VPA) - A52-55 (VPA)AlwaysBelow 1 Ω
    A31-5 (EPA) - A52-58 (EPA)AlwaysBelow 1 Ω
    A31-4 (VCPA) - A52-57 (VCPA)AlwaysBelow 1 Ω
    A31-3 (VPA2) - A52-56 (VPA2)AlwaysBelow 1 Ω
    A31-2 (EPA2) - A52-60 (EPA2)AlwaysBelow 1 Ω
    A31-1 (VCP2) - A52-59 (VCP2)AlwaysBelow 1 Ω
    A31-6 (VPA) or A52-55 (VPA) - Body groundAlways10 kΩ or higher
    A31-5 (EPA) or A52-58 (EPA) - Body groundAlways10 kΩ or higher
    A31-4 (VCPA) or A52-57 (VCPA) - Body groundAlways10 kΩ or higher
    A31-3 (VPA2) or A52-56 (VPA2) - Body groundAlways10 kΩ or higher
    A31-2 (EPA2) or A52-60 (EPA2) - Body groundAlways10 kΩ or higher
    A31-1 (VCP2) or A52-59 (VCP2) - Body groundAlways10 kΩ or higher
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
3.CHECK ECM (VCPA AND VCP2 VOLTAGE)
Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit. 1GR-FE ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

Disconnect the accelerator pedal sensor assembly connector.

Turn the ignition switch to ON.

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

  • Standard Voltage:
  • Tester ConnectionSwitch ConditionSpecified Condition
    A31-4 (VCPA) - A31-5 (EPA)Ignition switch ON4.5 to 5.5 V
    A31-1 (VCP2) - A31-2 (EPA2)Ignition switch ON4.5 to 5.5 V
Text in Illustration
*aFront view of wire harness connector
(to Accelerator Pedal Sensor Assembly)
NG
REPLACE ECM ()
OK
4.REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY

Replace the accelerator pedal sensor assembly ().

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

Connect the GTS to the DLC3.

Turn the ignition switch to ON and turn the GTS on.

Clear the DTCs ().

Start the engine.

Allow the engine to idle for 15 seconds.

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

Read the DTCs.

Result
ResultProceed to
P2120, P2122, P2123, P2125, P2127, P2128 and/or P2138 is outputA
No DTC is outputB
B
SYSTEM OK
A
REPLACE ECM ()