2Gr-Fe Engine Control System. Dtc P0120 Throttle / Pedal Position Sensor / Switch A Circuit Malfunction

The Throttle Position (TP) sensor is mounted on the throttle body, and detects the opening angle of the throttle valve. 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 TP sensor has two sensor circuits which each transmits a signal, VTA1 and VTA2. VTA1 is used to detect the throttle valve angle and VTA2 is used to detect malfunctions in VTA1. The sensor signal voltages vary between 0 V and 5 V in proportion to the throttle valve opening angle, and are transmitted to the VTA terminals of the ECM.

As the valve closes, the sensor output voltage decreases and as the valve opens, the sensor output voltage increases. The ECM calculates the throttle valve opening angle according to these signals and controls the throttle actuator in response to driver inputs. These signals are also used in calculations such as air-fuel ratio correction, power increase correction and fuel-cut control.

Camry. Acv40 Gsv40.2Gr-Fe Engine Control System.Sfi System.
Dtc
P0120 Throttle / Pedal Position Sensor / Switch A Circuit Malfunction

DTC No.	DTC Detection Condition	Trouble Area
P0120	Output voltage of VTA1 quickly fluctuates beyond lower and upper malfunction thresholds for 2 seconds (1 trip detection logic)	Throttle Position (TP) sensor (built into throttle body) ECM
P0122	Output voltage of VTA1 is 0.2 V or less for 2 seconds (1 trip detection logic)	TP sensor (built into throttle body) Short in VTA1 circuit Open in VC circuit ECM
P0123	Output voltage of VTA1 is 4.535 V or more for 2 seconds (1 trip detection logic)	TP sensor (built into throttle body) Open in VTA1 circuit Open in E2 circuit Short between VC and VTA1 circuits ECM
P0220	Output voltage of VTA2 quickly fluctuates beyond lower and upper malfunction thresholds for 2 seconds (1 trip detection logic)	TP sensor (built into throttle body) ECM
P0222	Output voltage of VTA2 is 1.75 V or less for 2 seconds (1 trip detection logic)	TP sensor (built into throttle body) Short in VTA2 circuit Open in VC circuit ECM
P0223	Output voltage of VTA2 is 4.8 V or more, and VTA1 is between 0.2 V and 2.02 V, for 2 seconds (1 trip detection logic)	TP sensor (built into throttle body) Open in VTA2 circuit Open in E2 circuit Short between VC and VTA2 circuits ECM
P2135	Either condition (a) or (b) is met (1 trip detection logic): (a) Difference between output voltages of VTA1 and VTA2 is 0.02 V or less for 0.5 seconds or more (b) Output voltage of VTA1 is 0.2 V or less, and VTA2 is 1.75 V or less, for 0.4 seconds or more	Short between VTA1 and VTA2 circuits TP sensor (built into throttle body) ECM

HINT:

When any of these DTCs are set, check the throttle valve opening angle by entering the following menus on an intelligent tester: Powertrain / Engine / Data List / Throttle Sensor Position and Throttle Position No. 2.
Throttle Sensor Position denotes the VTA1 signal (expressed in percentages), and Throttle Position No. 2 denotes the VTA2 signal (expressed in voltages).

Reference (Normal Condition):
Tester Display
Accelerator Pedal Fully Released
Accelerator Pedal Fully Depressed
Throttle Sensor Position
10 to 24 %
64 to 96 %
Throttle Position No. 2
2.1 to 3.1 V
4.5 to 5.0 V

Reference (Normal Condition):
Tester Display	Accelerator Pedal Fully Released	Accelerator Pedal Fully Depressed
Throttle Sensor Position	10 to 24 %	64 to 96 %
Throttle Position No. 2	2.1 to 3.1 V	4.5 to 5.0 V

FAIL-SAFE

When any of these DTCs, as well as other DTCs relating to ETCS (Electronic Throttle Control System) malfunctions, are set, the ECM enters fail-safe mode. During fail-safe mode, the ECM cuts the current to the throttle actuator off, and the throttle valve is returned to a 6° throttle angle by the return spring. The ECM then adjusts the engine output by controlling the fuel injection (intermittent fuel-cut) and ignition timing, in accordance with the accelerator pedal opening angle, to allow the vehicle to continue at a minimal speed. If the accelerator pedal is depressed gently, the vehicle can be driven slowly.

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction (CAMRY_ACV40 RM000000PDS01FX.html).

1.READ VALUE USING THROTTLE POSITION SENSOR (THROTTLE POS AND THROTTLE POS #2)

Connect the intelligent tester to the DLC3.

Turn the ignition switch to the ON position and turn the intelligent tester on.

Enter the following menus: Powertrain / Engine / Data List / Throttle Sensor Position and Throttle Position No. 2.

Check the values displayed on the tester.

Result:

TP#1 (VTA1) When AP Released	TP#2 (VTA2) When AP Released	TP#1 (VTA1) When AP Depressed	TP#2 (VTA2) When AP Depressed	Trouble Area	Proceed to
0 %	Between 0 V and 0.2 V	0 %	Between 0 V and 0.2 V	VC circuit open	A
100 %	Between 4.5 V and 5.0 V	100 %	Between 4.5 V and 5.0 V	E2 circuit open	A
0 % or 100 %	Between 2.1 V and 3.1 V (Fail-safe)	0 % or 100 %	Between 2.1 V and 3.1 V (Fail-safe)	VTA1 circuit open or ground short	A
Approx. 19 % (Fail-safe)	Between 0 V and 0.2 V, or 4.5 V and 5.0 V	Between 10 % and 24 % (Fail-safe)	Between 0 V and 0.2 V, or 4.5 V and 5.0 V	VTA2 circuit open or ground short	A
Between 10 % and 24 %	Between 2.1 V and 3.1 V	Between 64 % and 96 % (Not fail-safe)	Between 4.5 V and 5.0 V (Not fail-safe)	TP sensor circuit normal	B

HINT:

TP#1 denotes Throttle Sensor Position, and TP#2 denotes Throttle Position No. 2.
AP denotes Accelerator Pedal.
VTA1 is expressed as percentages, and VTA2 is expressed as voltages.

Go to step 5

A

2.CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)

Disconnect the C5 throttle body connector.

Disconnect the C58 (RHD) or C55 (LHD) ECM connector.

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

Standard resistance (Check for open):

RHD:

Tester Connection	Specified Condition
VC (C5-5) - VCTA (C58-96)	Below 1 Ω
VTA (C5-6) - VTA1 (C58-98)	Below 1 Ω
VTA2 (C5-4) - VTA2 (C58-99)	Below 1 Ω
E2 (C5-3) - ETA (C58-97)	Below 1 Ω

LHD:

Tester Connection	Specified Condition
VC (C5-5) - VCTA (C55-96)	Below 1 Ω
VTA (C5-6) - VTA1 (C55-98)	Below 1 Ω
VTA2 (C5-4) - VTA2 (C55-99)	Below 1 Ω
E2 (C5-3) - ETA (C55-97)	Below 1 Ω

Standard resistance (Check for short):

RHD:

Tester Connection	Specified Condition
VC (C5-5) or VCTA (C58-96) - Body ground	10 kΩ or higher
VTA (C5-6) or VTA1 (C58-98) - Body ground	10 kΩ or higher
VTA2 (C5-4) or VTA2 (C58-99) - Body ground	10 kΩ or higher
E2 (C5-3) - ETA (C58-97) - Body ground	10 kΩ or higher

LHD:

Tester Connection	Specified Condition
VC (C5-5) or VCTA (C55-96) - Body ground	10 kΩ or higher
VTA (C5-6) or VTA1 (C55-98) - Body ground	10 kΩ or higher
VTA2 (C5-4) or VTA2 (C55-99) - Body ground	10 kΩ or higher
E2 (C5-3) - ETA (C55-97) - Body ground	10 kΩ or higher

Reconnect the throttle body connector.

Reconnect the ECM connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.INSPECT ECM (VC VOLTAGE)

Disconnect the C5 throttle body connector.

Turn the ignition switch to the ON position.

Measure the voltage according to the value(s) in the table below.
Standard voltage:
Tester Connection
Specified Condition
VC (C5-5) - E2 (C5-3)
4.5 to 5.0 V

Reconnect the throttle body connector.

REPLACE ECM (CAMRY_ACV40 RM0000022NT002X.html)

OK

4.REPLACE THROTTLE BODY

Replace the throttle body (CAMRY_ACV40 RM0000022NL002X.html).

NEXT

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

Connect the intelligent tester to the DLC3.

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

Clear the DTCs (CAMRY_ACV40 RM000000PDK01VX.html).

Start the engine.

Allow the engine to idle for 15 seconds or more.

Enter the following menus: Powertrain / Engine / DTC.

Read the DTCs.

Result:

Display (DTC Output)
Proceed to
P0120, P0122, P0123, P0220, P0223, and/or P2135
A
No output
B

SYSTEM IS OK

REPLACE ECM (CAMRY_ACV40 RM0000022NT002X.html)

Tester Connection	Specified Condition
VC (C5-5) - E2 (C5-3)	4.5 to 5.0 V

Display (DTC Output)	Proceed to
P0120, P0122, P0123, P0220, P0223, and/or P2135	A
No output	B