Lexus NX: Throttle / Pedal Position Sensor / Switch "D" Circuit (P2120-152,...,P2138-154)

Lexus NX Service Manual / Engine & Hybrid System / 2ar-fxe (hybrid / Battery Control) / Hybrid Control System / Throttle / Pedal Position Sensor / Switch "D" Circuit (P2120-152,...,P2138-154)

DESCRIPTION

The accelerator pedal position sensor is mounted on the accelerator pedal to detect how much the pedal is depressed. This is a non-contact sensor with Hall elements. There are 2 outputs from the sensor. One is used to detect the accelerator pedal position and the other is used as a confirmation to allow the detection of a malfunction in the sensor itself. Voltage is output from the accelerator pedal position sensor to terminals VPA and VPA2 of the hybrid vehicle control ECU. This voltage varies from 0 to 5 V in accordance with the accelerator pedal position. Terminal VPA2 is primarily used to detect a malfunction in the sensor itself. The hybrid vehicle control ECU determines the current accelerator pedal position and controls the hybrid control system based on signals received by terminals VPA and VPA2.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate
P2120-152	Throttle / Pedal Position Sensor / Switch "D" Circuit	Main sensor circuit wiring malfunction or level is not stable: Main sensor voltage is 0.4 V or less or 4.8 V or more for a certain period of time. (Both of the following conditions are met: The main sensor voltage is 0.4 V or less for a certain period of time and 4.8 V or more for a certain period of time.) (1 trip detection logic)	Wire harness or connector Accelerator pedal sensor assembly Hybrid vehicle control ECU	Comes on	Master Warning Light: Comes on
P2121-106	Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance	Internal malfunction in the main sensor: Main sensor output changes rapidly (detected when there are no circuit malfunctions such as an open or short). (1 trip detection logic)	Wire harness or connector Accelerator pedal sensor assembly Hybrid vehicle control ECU	Comes on	Master Warning Light: Comes on
P2122-104	Throttle / Pedal Position Sensor / Switch "D" Circuit Low Input	Open or short to ground in the main sensor circuit: The main sensor voltage is 0.4 V or less for 0.5 seconds. (1 trip detection logic)	Wire harness or connector Accelerator pedal sensor assembly Hybrid vehicle control ECU	Comes on	Master Warning Light: Comes on
P2123-105	Throttle / Pedal Position Sensor / Switch "D" Circuit High Input	Short to +B in the main sensor circuit: The main sensor voltage is 4.8 V or more for 2 seconds. (1 trip detection logic)	Wire harness or connector Accelerator pedal sensor assembly Hybrid vehicle control ECU	Comes on	Master Warning Light: Comes on
P2125-153	Throttle / Pedal Position Sensor / Switch "E" Circuit	Sub sensor circuit wiring malfunction or level is not stable: When the main sensor circuit is normal, the sub sensor voltage is 1.2 V or less or 4.8 V or more for a certain period of time. (Both of the following conditions are met: Sub sensor voltage is 1.2 V or less for a certain period of time, and the main sensor is normal and sub sensor voltage is 4.8 V or more for a certain period of time.) (1 trip detection logic)	Wire harness or connector Accelerator pedal sensor assembly Hybrid vehicle control ECU	Comes on	Master Warning Light: Comes on
P2126-109	Throttle / Pedal Position Sensor / Switch "E" Circuit Range / Performance	Internal malfunction of the sub sensor: Sub sensor output changes rapidly (detected when there are no circuit malfunctions such as an open or short). (1 trip detection logic)	Wire harness or connector Accelerator pedal sensor assembly Hybrid vehicle control ECU	Comes on	Master Warning Light: Comes on
P2127-107	Throttle / Pedal Position Sensor / Switch "E" Circuit Low Input	Open or short to ground in the sub sensor circuit: The sub sensor voltage is 1.2 V or less for 0.5 seconds. (1 trip detection logic)	Wire harness or connector Accelerator pedal sensor assembly Hybrid vehicle control ECU	Comes on	Master Warning Light: Comes on
P2128-108	Throttle / Pedal Position Sensor / Switch "E" Circuit High Input	Short to +B in the sub sensor circuit: Main sensor is normal and sub sensor voltage is 4.8 V or more for 2 seconds. (1 trip detection logic)	Wire harness or connector Accelerator pedal sensor assembly Hybrid vehicle control ECU	Comes on	Master Warning Light: Comes on
P2138-110	Throttle / Pedal Position Sensor / Switch "D" / "E" Voltage Correlation	Difference between the main sensor value and sub sensor value is large. (1 trip detection logic)	Wire harness or connector Accelerator pedal sensor assembly Hybrid vehicle control ECU	Comes on	Master Warning Light: Comes on
P2138-154	Throttle / Pedal Position Sensor / Switch "D" / "E" Voltage Correlation	Main or sub sensor circuit wiring malfunction: The difference in voltage between the main sensor and sub sensor is 0.02 V or less, or a low output malfunction continues in both the main and sub sensors for a certain period of time. (1 trip detection logic)	Wire harness or connector Accelerator pedal sensor assembly Hybrid vehicle control ECU	Comes on	Master Warning Light: Comes on

Related Data List

DTC No.	Data List
P2120-152	Accel Pedal Pos #1 Accel Pedal Pos #2
P2121-106
P2122-104
P2123-105
P2125-153
P2126-109
P2127-107
P2128-108
P2138-110
P2138-154

MONITOR DESCRIPTION

The hybrid vehicle control ECU calculates the differences of the voltage of main accelerator sensor and sub accelerator sensor. If the differences exceed prescribed values, the hybrid vehicle control ECU determines that there is a malfunction in the accelerator sensor circuit. If the hybrid vehicle control ECU detects this malfunction, it will illuminate the MIL and store a DTC.

MONITOR STRATEGY

Related DTCs	P2123 (INF 105): Accelerator Pedal Position Sensor (APP Sensor) Sensor 1 Range Check (High voltage) P2122 (INF 104): Accelerator Pedal Position Sensor (APP Sensor) Sensor 1 Range Check (Low voltage) P2121 (INF 106): Throttle/Pedal Position Sensor/Switch "D" Voltage Out of Range P2120 (INF 152): Accelerator Pedal Position Sensor (APP Sensor) Sensor 1 Range Check (Chattering) P2128 (INF 108): Accelerator Pedal Position Sensor (APP Sensor) Sensor 2 Range Check (High voltage) P2127 (INF 107): Accelerator Pedal Position Sensor (APP Sensor) Sensor 2 Range Check (Low voltage) P2126 (INF 109): Throttle/Pedal Position Sensor/Switch "E" Voltage Out of Range P2125 (INF 153): Accelerator Pedal Position Sensor (APP Sensor) Sensor 2 Range Check (Chattering) P2138 (INF 110): Throttle/Pedal Position Sensor/Switch "D"/"E" Voltage Correlation P2138 (INF 154): Accelerator Pedal Position Sensor (APP Sensor) Correlation
Required sensors/components	Throttle/Pedal Position Sensor/Switch
Frequency of operation	Continuous
Duration	TMC's intellectual property
MIL operation	Immediately / 1 driving cycle
Sequence of operation	None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever the following DTCs are not stored	TMC's intellectual property
Other conditions belong to TMC's intellectual property	-

TYPICAL MALFUNCTION THRESHOLDS

TMC's intellectual property

COMPONENT OPERATING RANGE

Hybrid vehicle control ECU

DTC P2123 (INF 105) is not detected

DTC P2122 (INF 104) is not detected

DTC P2121 (INF 106) is not detected

DTC P2120 (INF 152) is not detected

DTC P2128 (INF 108) is not detected

DTC P2127 (INF 107) is not detected

DTC P2126 (INF 109) is not detected

DTC P2125 (INF 153) is not detected

DTC P2138 (INF 110) is not detected

DTC P2138 (INF 154) is not detected

CONFIRMATION DRIVING PATTERN

HINT:

After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
Click here
When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.
Click here

Connect the Techstream to the DLC3.
Turn the power switch on (IG) and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the power switch off and wait for 2 minutes or more.
Turn the power switch on (IG) and turn the Techstream on.
Wait for approximately 10 seconds with the power switch on (READY) and shift lever in P, then fully depress and release the accelerator pedal several times.
Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.
Read the current DTCs.
HINT:
- If a current DTC is output, the system is malfunctioning.
- If current DTCs are not output, check for permanent DTCs.
Check that the permanent DTCs are cleared.
If the permanent DTCs are not cleared, perform the universal trip, and then check for permanent DTCs again.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.

Wait for approximately 10 seconds with the power switch on (READY) and the shift lever in P, then fully depress and release the accelerator pedal several times.

PROCEDURE

1.	READ VALUE USING TECHSTREAM (ACCEL PEDAL POS #1, ACCEL PEDAL POS #2)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

Powertrain > Hybrid Control > Data List

Tester Display
Accel Pedal Pos #1
Accel Pedal Pos #2

(d) Read the Data List.

Standard:

Tester Display	Accelerator Pedal Condition	Specified Condition
Accel Pedal Pos #1	Not depressed	10 to 22%
	Fully depressed	52 to 90%
	Not depressed → Fully depressed → Not depressed (Accelerator pedal should be operated slowly)	Value changes progressively
Accel Pedal Pos #2	Not depressed	24 to 40%
	Fully depressed	68 to 99%
	Not depressed → Fully depressed → Not depressed (Accelerator pedal should be operated slowly)	Value changes progressively

(e) Turn the power switch off.

CHECK FOR INTERMITTENT PROBLEMS

2.	CHECK CONNECTOR CONNECTION CONDITION (ACCELERATOR PEDAL SENSOR ASSEMBLY CONNECTOR)

(a) Check the connector connections and contact pressure of the relevant terminals for the accelerator pedal sensor assembly connector.

Click here

OK:

The connectors are connected securely and there are no contact pressure problems.

CONNECT SECURELY

3.	CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)

Click here

CONNECT SECURELY

4.	CHECK HYBRID VEHICLE CONTROL ECU (CHECK VOLTAGE)

(a) Disconnect the A2 accelerator pedal sensor assembly connector.

(b) Turn the power switch on (IG).

Standard Voltage:

Tester Connection	Condition	Specified Condition
A2-4 (VCPA) - A2-5 (EPA)	Power switch on (IG)	4.5 to 5.5 V
A2-1 (VCP2) - A2-2 (EPA2)	Power switch on (IG)	4.5 to 5.5 V

*a	Front view of wire harness connector (to Accelerator Pedal Sensor Assembly)

(d) Turn the power switch off.

(e) Reconnect the A2 accelerator pedal sensor assembly connector.

GO TO STEP 6

5.	CHECK HYBRID VEHICLE CONTROL ECU (CHECK RESISTANCE)

(a) Disconnect the A2 accelerator pedal sensor assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A2-6 (VPA) - A2-5 (EPA)	Power switch off	36.60 to 41.61 kΩ
A2-3 (VPA2) - A2-2 (EPA2)	Power switch off	36.60 to 41.61 kΩ

*a	Front view of wire harness connector (to Accelerator Pedal Sensor Assembly)

REPLACE ACCELERATOR PEDAL(W/SENSOR) ROD ASSEMBLY

GO TO STEP 7

6.	CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - ACCELERATOR PEDAL SENSOR ASSEMBLY)

(a) Disconnect the A60 hybrid vehicle control ECU connector.

(b) Disconnect the A2 accelerator pedal sensor assembly connector.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A60-9 (VCPA) - Body ground	Power switch on (IG)	Below 1 V
A60-20 (EPA) - Body ground	Power switch on (IG)	Below 1 V
A60-8 (VCP2) - Body ground	Power switch on (IG)	Below 1 V
A60-18 (EPA2) - Body ground	Power switch on (IG)	Below 1 V

NOTICE:

Turning the power switch on (IG) with the hybrid vehicle control ECU connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

Rear view of wire harness connector

(to Hybrid Vehicle Control ECU)

Front view of wire harness connector

(to Accelerator Pedal Sensor Assembly)

(e) Turn the power switch off.

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

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
A60-9 (VCPA) - A2-4 (VCPA)	Power switch off	Below 1 Ω
A60-20 (EPA) - A2-5 (EPA)	Power switch off	Below 1 Ω
A60-8 (VCP2) - A2-1 (VCP2)	Power switch off	Below 1 Ω
A60-18 (EPA2) - A2-2 (EPA2)	Power switch off	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
A60-9 (VCPA) or A2-4 (VCPA) - Body ground and other terminals	Power switch off	10 kΩ or higher
A60-20 (EPA) or A2-5 (EPA) - Body ground and other terminals	Power switch off	10 kΩ or higher
A60-8 (VCP2) or A2-1 (VCP2) - Body ground and other terminals	Power switch off	10 kΩ or higher
A60-18 (EPA2) or A2-2 (EPA2) - Body ground and other terminals	Power switch off	10 kΩ or higher

(g) Reconnect the A2 accelerator pedal sensor assembly connector.

(h) Reconnect the A60 hybrid vehicle control ECU connector.

REPLACE HYBRID VEHICLE CONTROL ECU

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - ACCELERATOR PEDAL SENSOR ASSEMBLY)

(a) Disconnect the A60 hybrid vehicle control ECU connector.

(b) Disconnect the A2 accelerator pedal sensor assembly connector.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A60-30 (VPA) - Body ground	Power switch on (IG)	Below 1 V
A60-28 (VPA2) - Body ground	Power switch on (IG)	Below 1 V
A60-20 (EPA) - Body ground	Power switch on (IG)	Below 1 V
A60-18 (EPA2) - Body ground	Power switch on (IG)	Below 1 V

NOTICE:

Turning the power switch on (IG) with the hybrid vehicle control ECU connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

Rear view of wire harness connector

(to Hybrid Vehicle Control ECU)

Front view of wire harness connector

(to Accelerator Pedal Sensor Assembly)

(e) Turn the power switch off.

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

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
A60-30 (VPA) - A2-6 (VPA)	Power switch off	Below 1 Ω
A60-20 (EPA) - A2-5 (EPA)	Power switch off	Below 1 Ω
A60-28 (VPA2) - A2-3 (VPA2)	Power switch off	Below 1 Ω
A60-18 (EPA2) - A2-2 (EPA2)	Power switch off	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
A60-30 (VPA) or A2-6 (VPA) - Body ground and other terminals	Power switch off	10 kΩ or higher
A60-20 (EPA) or A2-5 (EPA) - Body ground and other terminals	Power switch off	10 kΩ or higher
A60-28 (VPA2) or A2-3 (VPA2) - Body ground and other terminals	Power switch off	10 kΩ or higher
A60-18 (EPA2) or A2-2 (EPA2) - Body ground and other terminals	Power switch off	10 kΩ or higher

(g) Reconnect the A2 accelerator pedal sensor assembly connector.

(h) Reconnect the A60 hybrid vehicle control ECU connector.

REPLACE HYBRID VEHICLE CONTROL ECU

REPAIR OR REPLACE HARNESS OR CONNECTOR

SEE MORE:

Precaution

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Problem Symptoms Table

PROBLEM SYMPTOMS TABLE HINT: Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspect

Lexus NX: Throttle / Pedal Position Sensor / Switch "D" Circuit (P2120-152,...,P2138-154)

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Precaution

Problem Symptoms Table