READ VALUE USING INTELLIGENT TESTER (ACCELERATOR PEDAL POSITION)
CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR - ECM)
INSPECT ECM TERMINAL VOLTAGE (VCPA AND VCP2 TERMINALS)
REPLACE ACCELERATOR PEDAL ROD ASSEMBLY
REPAIR OR REPLACE HARNESS OR CONNECTOR
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
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 is the repair procedure for the accelerator pedal position sensor.
- This electrical throttle system does not use a throttle cable.
- This accelerator pedal position sensor is a non-contact type.
In the accelerator pedal position sensor, the voltage applied to terminals VPA and VPA2 of the ECM changes between 0 V and 5 V in proportion to the opening angle of the accelerator pedal. The VPA is a signal to indicate the actual accelerator pedal opening angle which is used for engine control, and the VPA2 is a signal to indicate information about the opening angle which is used for detecting malfunctions. The ECM determines the current opening angle of the accelerator pedal using signals from terminals VPA and VPA2, and the ECM controls the throttle motor based on these signals.

DTC Detection Drive Pattern | DTC Detection Condition | Trouble Area |
Ignition switch ON
| Condition (a) continues for 0.5 seconds (1 trip detection logic): (a) VPA is below 0.4 V and VPA2 is more than 2.7 deg, or VPA is higher than 4.8 V. |
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DTC Detection Drive Pattern | DTC Detection Condition | Trouble Area |
Ignition switch ON
| Conditions (a) and (b) continue for 0.5 seconds (1 trip detection logic): (a) VPA is below 0.4 V. (b) VPA2 is more than 2.7 deg. |
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DTC Detection Drive Pattern | DTC Detection Condition | Trouble Area |
Ignition switch ON
| Condition (a) continues for 2.0 seconds (1 trip detection logic): (a) VPA is higher than 4.8 V. |
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DTC Detection Drive Pattern | DTC Detection Condition | Trouble Area |
Ignition switch ON
| Condition (a) continues for 0.5 seconds (1 trip detection logic): (a) VPA2 is below 1.2 V and VPA is more than 2.7 deg, or VPA2 is higher than 4.8 V and VPA is higher than 0.4 V but below 3.45 V. |
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DTC Detection Drive Pattern | DTC Detection Condition | Trouble Area |
Ignition switch ON
| Conditions (a) and (b) continue for 0.5 seconds (1 trip detection logic): (a) VPA2 is below 1.2 V. (b) VPA1 is more than 2.7 deg. |
|
DTC Detection Drive Pattern | DTC Detection Condition | Trouble Area |
Ignition switch ON
| Conditions (a) and (b) continue for 2.0 seconds (1 trip detection logic): (a) VPA2 is higher than 4.8 V. (b) VPA is higher than 0.4 V but below 3.45 V. |
|
DTC Detection Drive Pattern | DTC Detection Condition | Trouble Area |
Ignition switch ON
| Conditions (a) or (b) continue for 2.0 seconds (1 trip detection logic): (a) The difference between VPA and VPA2 is less than 0.02 V. (b) VPA is below 0.4 V and VPA2 is below 1.2 V. |
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DTC No. | Data List |
P2120 |
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P2122 | |
P2123 | |
P2125 | |
P2127 | |
P2128 | |
P2138 |
WIRING DIAGRAM

INSPECTION PROCEDURE
- NOTICE:
- After replacing the ECM, the new ECM needs registration (LandCruiser RM0000012XK0ARX.html) and initialization (LandCruiser RM000000TIN08CX.html).
- HINT:
- 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, and other data from the time the malfunction occurred.
1.READ VALUE USING INTELLIGENT TESTER (ACCELERATOR PEDAL POSITION) |
Connect the intelligent tester to the DLC3.
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Turn the ignition switch to ON and turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / Data List / Accel Sens. No.1 Volt % and Accel Sens. No.2 Volt %.
Read the values.
- Standard Voltage:
Accelerator Pedal Accel Sens. No.1 Volt % Accel Sens. No.2 Volt % Released 8 to 28% 51 to 86% Depressed 30 to 55% 73 to 98%
Text in Illustration *1 Accelerator pedal assembly *a Depressed *b Released Result Result Proceed to NG A OK B
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A | |
2.CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR - ECM) |
Disconnect the accelerator pedal position sensor connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Open):
Tester Connection Condition Specified Condition A19-1 (VCP2) - G58-4 (VCP2) Always Below 1 Ω A19-2 (EPA2) - G58-3 (EPA2) Always Below 1 Ω A19-3 (VPA2) - G57-1 (VPA2) Always Below 1 Ω A19-4 (VCPA) - G58-6 (VCPA) Always Below 1 Ω A19-5 (EPA) - G58-5 (EPA) Always Below 1 Ω A19-6 (VPA) - G57-2 (VPA) Always Below 1 Ω
- Standard Resistance (Check for Short):
Tester Connection Condition Specified Condition A19-1 (VCP2) or G58-4 (VCP2) - Body ground Always 10 kΩ or higher A19-2 (EPA2) or G58-3 (EPA2) - Body ground Always 10 kΩ or higher A19-3 (VPA2) or G57-1 (VPA2) - Body ground Always 10 kΩ or higher A19-4 (VCPA) or G58-6 (VCPA) - Body ground Always 10 kΩ or higher A19-5 (EPA) or G58-5 (EPA) - Body ground Always 10 kΩ or higher A19-6 (VPA) or G57-2 (VPA) - Body ground Always 10 kΩ or higher
Reconnect the accelerator pedal position sensor connector.
Reconnect the ECM connector.
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OK | |
3.INSPECT ECM TERMINAL VOLTAGE (VCPA AND VCP2 TERMINALS) |
Disconnect the accelerator pedal position sensor connector.
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Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection Switch Condition Specified Condition A19-4 (VCPA) - A19-5 (EPA) Ignition switch ON 4.5 to 5.5 V A19-1 (VCP2) - A19-2 (EPA2) Ignition switch ON 4.5 to 5.5 V
Text in Illustration *a Front view of wire harness connector
(to accelerator pedal position sensor)
Reconnect the accelerator pedal position sensor connector.
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OK | |
4.REPLACE ACCELERATOR PEDAL ROD ASSEMBLY |
Replace the accelerator pedal rod assembly (LandCruiser RM00000463000BX.html).
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5.REPLACE ECM |
Replace the ECM (LandCruiser RM0000013Z002CX.html).
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6.REPAIR OR REPLACE HARNESS OR CONNECTOR |
Repair or replace the harness or connector.
NEXT | |
7.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED |
Connect the intelligent tester to the DLC3.
Clear the DTCs (LandCruiser RM000000PDK1DJX.html).
Turn the ignition switch off and leave the vehicle for 30 seconds.
Turn the ignition switch to ON.
Fully release the accelerator pedal for 3 seconds or more, then depress it partway for 3 seconds or more, and then fully depress it for 3 seconds or more.
Confirm that the DTC is not output again.
NEXT | ||
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