The accelerator pedal position sensor assembly is mounted on the accelerator pedal bracket 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 4.75 V in proportion to the position of the accelerator pedal (throttle valve). 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.

HINT:

This ETCS (Electronic Throttle Control System) does not use a throttle cable.

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

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).	Accelerator pedal position sensor assembly ECM
P2122	VPA 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 position sensor assembly Open in VCP1 circuit Open or ground short in VPA circuit ECM
P2123	VPA is 4.8 V or higher for 2.0 seconds or more (1 trip detection logic).	Accelerator pedal position sensor assembly Open in EPA circuit ECM
P2125	VPA2 fluctuates rapidly beyond the upper and lower malfunction thresholds for 0.5 seconds or more (1 trip detection logic).	Accelerator pedal position sensor assembly ECM
P2127	VPA2 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 position sensor assembly Open in VCP2 circuit Open or ground short in VPA2 circuit 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 0.4 V and 3.45 V.	Accelerator pedal position sensor assembly Open in EPA2 circuit ECM
P2138	Condition (a) or (b) continues 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 position sensor assembly ECM

HINT:

When any of these DTCs are stored, check the accelerator pedal position sensor voltage by entering the following menus: Powertrain / Engine and ECT / Data List / All Data / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.

Trouble Area	Accel 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 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 4.7 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
EPA circuit open	4.5 to 5.5 V	4.5 to 5.5 V	4.5 to 5.5 V	4.5 to 5.5 V
Normal condition	0.5 to 1.1 V	1.2 to 2.0 V	2.6 to 4.5 V	3.4 to 4.75 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.

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.

CONFIRMATION DRIVING PATTERN

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

Connect the GTS to the DLC3.

Turn the engine switch on (IG) and turn the GTS on.

Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).

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

Turn the engine switch on (IG) and turn the GTS on [A].

Fully depress and release the accelerator pedal [B].

Check that 5 seconds or more have elapsed since the engine switch was turned on (IG).

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

Read the pending DTCs.

HINT:

If a pending DTC is output, the system is malfunctioning.

If a pending DTC is not output, perform the following procedure.

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Input the DTC: P2120, P2122, P2123, P2125, P2127, P2128 or P2138.

Check the DTC judgment result.

GTS Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

HINT:

If the judgment result shows NORMAL, the system is normal.

If the judgment result shows ABNORMAL, the system has a malfunction.

If the judgment result shows INCOMPLETE or N/A, perform steps [B] through [C] again.

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 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.

The ECM continues operating in fail-safe mode until a pass condition is detected, and the engine switch is then turned off.

WIRING DIAGRAM

Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit. 1UR-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 (ACCELERATOR PEDAL POSITION SENSOR)

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

Connect the GTS to the DLC3.

Turn the engine switch on (IG).

Turn the GTS on.

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

Read the value displayed on the GTS.

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 4.75 V	More than 0.02 V

Text in Illustration
*a	Depressed
*b	Released

Go to step 5

Go to step 2

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:

for RHD
Tester Connection	Condition	Specified Condition
A31-6 (VPA) - A52-55 (VPA)	Always	Below 1 Ω
A31-5 (EPA) - A52-58 (EPA)	Always	Below 1 Ω
A31-4 (VCPA) - A52-57 (VCPA)	Always	Below 1 Ω
A31-3 (VPA2) - A52-56 (VPA2)	Always	Below 1 Ω
A31-2 (EPA2) - A52-60 (EPA2)	Always	Below 1 Ω
A31-1 (VCP2) - A52-59 (VCP2)	Always	Below 1 Ω
A31-6 (VPA) or A52-55 (VPA) - Body ground	Always	10 kΩ or higher
A31-5 (EPA) or A52-58 (EPA) - Body ground	Always	10 kΩ or higher
A31-4 (VCPA) or A52-57 (VCPA) - Body ground	Always	10 kΩ or higher
A31-3 (VPA2) or A52-56 (VPA2) - Body ground	Always	10 kΩ or higher
A31-2 (EPA2) or A52-60 (EPA2) - Body ground	Always	10 kΩ or higher
A31-1 (VCP2) or A52-59 (VCP2) - Body ground	Always	10 kΩ or higher

for LHD
Tester Connection	Condition	Specified Condition
A31-6 (VPA) - A38-55 (VPA)	Always	Below 1 Ω
A31-5 (EPA) - A38-58 (EPA)	Always	Below 1 Ω
A31-4 (VCPA) - A38-57 (VCPA)	Always	Below 1 Ω
A31-3 (VPA2) - A38-56 (VPA2)	Always	Below 1 Ω
A31-2 (EPA2) - A38-60 (EPA2)	Always	Below 1 Ω
A31-1 (VCP2) - A38-59 (VCP2)	Always	Below 1 Ω
A31-6 (VPA) or A38-55 (VPA) - Body ground	Always	10 kΩ or higher
A31-5 (EPA) or A38-58 (EPA) - Body ground	Always	10 kΩ or higher
A31-4 (VCPA) or A38-57 (VCPA) - Body ground	Always	10 kΩ or higher
A31-3 (VPA2) or A38-56 (VPA2) - Body ground	Always	10 kΩ or higher
A31-2 (EPA2) or A38-60 (EPA2) - Body ground	Always	10 kΩ or higher
A31-1 (VCP2) or A38-59 (VCP2) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.INSPECT ECM (VCPA AND VCP2 VOLTAGE)

Disconnect the accelerator pedal position sensor connector.

Turn the engine switch on (IG).

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

Standard Voltage:
Tester Connection Switch Condition Specified Condition
A31-4 (VCPA) - A31-5 (EPA) Engine switch on (IG) 4.5 to 5.5 V
A31-1 (VCP2) - A31-2 (EPA2) Engine switch on (IG) 4.5 to 5.5 V

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

REPLACE ECM ()

OK

4.REPLACE ACCELERATOR PEDAL POSITION SENSOR ASSEMBLY

Replace the accelerator pedal position sensor assembly ().

NEXT

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

Connect the GTS to the DLC3.

Turn the engine switch on (IG).

Turn the GTS on.

Clear DTCs ().

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

Read DTCs.

Result
Result	Proceed to
P2120, P2122, P2123, P2125, P2127, P2128 and/or P2138 is output	A
No DTC is output	B

END

REPLACE ECM ()

Tester Connection	Switch Condition	Specified Condition
A31-4 (VCPA) - A31-5 (EPA)	Engine switch on (IG)	4.5 to 5.5 V
A31-1 (VCP2) - A31-2 (EPA2)	Engine switch on (IG)	4.5 to 5.5 V