1Nz-Fe Engine Control. Dtc P0120 Throttle / Pedal Position Sensor / Switch A Circuit Malfunction

The TP sensor is mounted on the throttle with motor body assembly, 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.

Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan).
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 when accelerator pedal depressed (1 trip detection logic)	Throttle with motor body assembly ECM
P0121	Difference between VTA1 and VTA2 voltages less than 0.8 V, or more than 1.6 V for 2 seconds (1 trip detection logic)	Throttle with motor body assembly TP sensor circuit ECM
P0122	Output voltage of VTA1 0.2 V or less for 2 seconds when accelerator pedal depressed (1 trip detection logic)	Throttle with motor body assembly Short in VTA1 circuit Open in VC circuit ECM
P0123	Output voltage of VTA1 4.535 V or more for 2 seconds when accelerator pedal depressed (1 trip detection logic)	Throttle with motor body assembly 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 when accelerator pedal depressed (1 trip detection logic)	Throttle with motor body assembly ECM
P0222	Output voltage of VTA2 1.75 V or less for 2 seconds when accelerator pedal depressed (1 trip detection logic)	Throttle with motor body assembly Short in VTA2 circuit Open in VC circuit ECM
P0223	Output voltage of VTA2 4.8 V or more, and VTA1 between 0.2 V and 2.02 V for 2 seconds when accelerator pedal depressed (1 trip detection logic)	Throttle with motor body assembly Open in VTA2 circuit Open in E2 circuit Short between VC and VTA2 circuits ECM
P2135	Either condition (a) or (b) met (1 trip detection logic): (a) Difference between output voltages of VTA1 and VTA2 0.02 V or less for 0.5 seconds or more (b) Output voltage of VTA1 0.2 V or less, and VTA2 1.75 V or less, for 0.4 seconds or more	Short between VTA1 and VTA2 circuits Throttle with motor body assembly ECM

HINT:

When any of these DTCs are output, check the throttle valve opening angle by entering the following menus on the Techstream: Powertrain / Engine and ECT / Data List / Throttle Position No.1 and Throttle Position No.2.

Throttle Position No.1 denotes the VTA1 signal, and Throttle Position No.2 denotes the VTA2 signal.

Reference (Normal Condition):

Techstream Display
Accelerator Pedal Fully Released
Accelerator Pedal Fully Depressed
Throttle Position No.1
0.5 to 1.1 V
3.2 to 4.8 V
Throttle Position No.2
2.1 to 3.1 V
4.6 to 5.0 V

MONITOR DESCRIPTION

P0120, P0122, P0123, P0220, P0222, P0223, P2135
The ECM uses the Throttle Position (TP) sensor to monitor the throttle valve opening angle. There are several checks that the ECM performs to confirm the proper operation of the TP sensor.

A specific voltage difference is expected between the sensor terminals, VTA1 and VTA2, for each throttle valve opening angle. If the difference between VTA1 and VTA2 is incorrect, the ECM interprets this as a malfunction in the sensor, and stores a DTC.

VTA1 and VTA2 each have a specific voltage range. If VTA1 or VTA2 is outside the normal operating range, the ECM interprets this as a malfunction in the sensor, and stores a DTC.

VTA1 and VTA2 should never be close to the same voltage level. If VTA1 is within 0.02 V of VTA2, the ECM determines that there is a short circuit in the sensor, and stores a DTC.

If the malfunction is not repaired successfully, a DTC is stored 10 seconds after the engine is next started.
P0121
The ECM uses the TP sensor to monitor the throttle valve opening angle.
This sensor transmits two signals: VTA1 and VTA2. VTA1 is used to detect the throttle opening angle and VTA2 is used to detect malfunctions in VTA1. The ECM performs several checks to confirm the proper operation of the TP sensor and VTA1.
For each throttle opening angle, a specific voltage difference is expected between the outputs of VTA1 and VTA2. If the output voltage difference between the two signals deviates from the normal operating range, the ECM interprets this as a malfunction of the TP sensor. The ECM illuminates the MIL and stores the DTC.
If the malfunction is not repaired successfully, the DTC is stored 2 seconds after the engine is next started.

MONITOR STRATEGY

Related DTCs	P0120: Throttle position sensor 1 range check (Fluctuating) P0121: Throttle position sensor rationality P0122: Throttle position sensor 1 range check (Low voltage) P0123: Throttle position sensor 1 range check (High voltage) P0220: Throttle position sensor 2 range check (Fluctuating) P0222: Throttle position sensor 2 range check (Low voltage) P0223: Throttle position sensor 2 range check (High voltage) P2135: Throttle position sensor range check (Correlation)
Required Sensors/Components (Main)	Throttle position sensor
Required Sensors/Components (Related)	-
Frequency of Operation	Continuous
Duration	2 seconds: P0120, P0122, P0123, P0220, P0222 and P0223 within 2 seconds: P0121 0.5 seconds: P2135 Case 1 0.4 seconds: P2135 Case 2
MIL Operation	Immediate
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

P0120, P0122, P0123, P0220, P0222, P0223, P2135
Monitor runs whenever following DTCs not present	None
Either of following conditions A or B met	-
A. Ignition switch ON	0.012 seconds or more
B. Electronic throttle actuator power	ON

P0121
Monitor runs whenever following DTCs not present	None
Either of following conditions A or B met	-
A. Ignition switch	ON
B. Electric throttle motor power	ON
C. Throttle position sensor circuit fail (P0120, P0122, P0123, P0220, P0222, P0223, P2135)	Not detected

TYPICAL MALFUNCTION THRESHOLDS

P0120:
VTA1 voltage	0.2 V or less, or 4.535 V or more

P0121:
Either of following conditions met	-
Difference of learned TP sensor opener position voltage between VTA2 and VTA1	Higher than 1.6 V
Difference of learned TP sensor opener position voltage between VTA2 and VTA1	Below 0.8 V

P0122:
VTA1 voltage	0.2 V or less

P0123:
VTA1 voltage	4.535 V or more

P0220:
Either of the following condition A or B is met	-
A. VTA2 voltage	1.75 V or less
B. VTA2 voltage when the VTA1 is 0.2 to 2.02 V	4.8 V or more

P0222:
VTA2 voltage	1.75 V or less

P0223:
VTA2 voltage when VTA1 0.2 V or more, and 2.02 V or less	4.8 V or more

P2135 Case 1:
Difference between VTA1 and VTA2 voltages	0.02 V or less

P2135 Case 2:
VTA1 voltage	0.2 V or less
VTA2 voltage	1.75 V or less

COMPONENT OPERATING RANGE

VTA1 voltage	0.69 to 4.05 V
VTA2 voltage	2.25 to 4.8 V

CONFIRMATION DRIVING PATTERN

Connect the Techstream to the DLC3.
Turn the ignition switch to ON and turn the Techstream on.
Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the Techstream on [A].
Start the engine.
With the vehicle stationary, fully depress and release the accelerator pedal [B].
Idle the engine for 2 seconds or more [C].
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [D].
Read pending DTCs.
HINT:
1. If a pending DTC is output, the system is malfunctioning.
2. 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: P0120, P0121, P0122, P0123, P0220, P0222, P0223 or P2135.

Check the DTC judgment result.

Techstream 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 result shows INCOMPLETE or N/A, perform steps [B] through [D] again.

If no pending DTC is output, perform a universal trip and check for permanent DTCs (YARIS_NCP93 RM000000PDK0QGX.html).
HINT:
1. If a permanent DTC is output, the system is malfunctioning.
2. If no permanent DTC is output, the system is normal.

FAIL-SAFE

When any of these DTCs, or other DTCs relating to ETCS (Electronic Throttle Control System) malfunctions, are stored, the ECM enters fail-safe mode. During fail-safe mode, the ECM cuts off the current to the throttle actuator, 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 firmly and gently, the vehicle can be driven slowly.
Fail-safe mode continues until a pass condition is detected, and the ignition switch is then turned to OFF.

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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 TECHSTREAM (THROTTLE POSITION NO.1 AND THROTTLE POSITION NO.2)

Connect the Techstream to the DLC3.

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

Enter the following menus: Powertrain / Engine and ECT / Data List / Throttle Position No.1 and Throttle Position No.2.

Check the values displayed on the Techstream.

Result
When Accelerator Pedal Released		When Accelerator Pedal Depressed		Trouble Areas	Proceed to
Throttle Position No.1	Throttle Position No.2	Throttle Position No.1	Throttle Position No.2	Trouble Areas	Proceed to
0 V to 0.2 V	0 V to 0.2 V	0 V to 0.2 V	0 V to 0.2 V	VC circuit open	A
4.5 V to 5.0 V	4.5 V to 5.0 V	4.5 V to 5.0 V	4.5 V to 5.0 V	E2 circuit open
0 V to 0.2 V, or 4.5 V to 5.0 V	2.1 V to 3.1 V (Fail-safe)	0 V to 0.2 V, or 4.5 V to 5.0 V	2.1 V to 3.1 V (Fail-safe)	VTA1 circuit open or ground short
0.6 V to 1.4 V (Fail-safe)	0 V to 0.2 V, or 4.5 V to 5.0 V	0.6 V to 1.4 V (Fail-safe)	0 V to 0.2 V, or 4.5 V to 5.0 V	VTA2 circuit open or ground short
0.5 V to 1.1 V	2.1 V to 3.1 V	3.2 V to 4.8 V (Not fail-safe)	4.6 V to 5.0 V (Not fail-safe)	TP sensor circuit normal	B

HINT:

DTC P0121 is stored when the VTA1 and VTA2 output voltages are not consistent with the sensor characteristics. Therefore, check the freeze frame data when this DTC is stored. Use the following formula to confirm the relative differences in voltage.
Characteristic Sensor Output:
VTA2 x 0.8 is approximately equal to VTA1 + 1.11 V
VTA1: Throttle Position No. 1.
VTA2: Throttle Position No. 2.
If DTC P0121 is output, proceed to the "Check Harness and Connector (Throttle with Motor Body Assembly- ECM)".

Go to step 5

A

2.CHECK HARNESS AND CONNECTOR (THROTTLE WITH MOTOR BODY ASSEMBLY - ECM)

Disconnect the C17 throttle with motor body assembly connector.

Disconnect the C20 ECM connector.

Check the resistance.
Standard resistance (Check for open):
Tester Connections
Specified Conditions
VC (C17-5) - VCTA (C20-67)
Below 1 Ω
VTA (C17-6) - VTA1 (C20-115)
VTA2 (C17-4) - VTA2 (C20-114)
E2 (C17-3) - ETA (C20-91)
Standard resistance (Check for short):
Tester Connections
Specified Conditions
VC (C17-5) or VCTA (C20-67) - Body ground
10 kΩ or higher
VTA (C17-6) or VTA1 (C20-115) - Body ground
VTA2 (C17-4) or VTA2 (C20-114) - Body ground

Reconnect the throttle with motor body assembly connector.

Reconnect the ECM connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.INSPECT ECM (VC VOLTAGE)

Disconnect the C17 throttle with motor body assembly connector.

Turn the ignition switch to ON.

Measure the voltage between the terminals of the throttle with motor body assembly connector.
Standard voltage:
Tester Connections
Specified Conditions
VC (C17-5) - E2 (C17-3)
4.5 to 5.5 V

Reconnect the throttle with motor body assembly connector.

REPLACE ECM (YARIS_NCP93 RM000001CN002AX.html)

OK

4.REPLACE THROTTLE WITH MOTOR BODY ASSEMBLY

Replace the throttle with motor body assembly (YARIS_NCP93 RM000001CZA012X.html).

NEXT

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

Connect the Techstream to the DLC3.

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

Clear DTCs (YARIS_NCP93 RM000000PDK0QGX.html).

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

Read DTCs.

Result
Display (DTC Output)
Proceed To
P0120, P0121, P0122, P0123, P0220, P0222, P0223, and/or P2135
A
No output
B

Result
Display (DTC Output)	Proceed To
P0120, P0121, P0122, P0123, P0220, P0222, P0223, and/or P2135	A
No output	B

END

REPLACE ECM (YARIS_NCP93 RM000001CN002AX.html)

Techstream Display	Accelerator Pedal Fully Released	Accelerator Pedal Fully Depressed
Throttle Position No.1	0.5 to 1.1 V	3.2 to 4.8 V
Throttle Position No.2	2.1 to 3.1 V	4.6 to 5.0 V

Tester Connections	Specified Conditions
VC (C17-5) - VCTA (C20-67)	Below 1 Ω
VTA (C17-6) - VTA1 (C20-115)
VTA2 (C17-4) - VTA2 (C20-114)
E2 (C17-3) - ETA (C20-91)

Tester Connections	Specified Conditions
VC (C17-5) or VCTA (C20-67) - Body ground	10 kΩ or higher
VTA (C17-6) or VTA1 (C20-115) - Body ground
VTA2 (C17-4) or VTA2 (C20-114) - Body ground

Tester Connections	Specified Conditions
VC (C17-5) - E2 (C17-3)	4.5 to 5.5 V