SFI SYSTEM, Diagnostic DTC:P0120, P0121, P0122, P0123, P0220, P0222, P0223, P2135

DTC Code	DTC Name
P0120	Throttle / Pedal Position Sensor / Switch "A" Circuit Malfunction
P0121	Throttle / Pedal Position Sensor / Switch "A" Circuit Range / Performance Problem
P0122	Throttle / Pedal Position Sensor / Switch "A" Circuit Low Input
P0123	Throttle / Pedal Position Sensor / Switch "A" Circuit High Input
P0220	Throttle / Pedal Position Sensor / Switch "B" Circuit
P0222	Throttle / Pedal Position Sensor / Switch "B" Circuit Low Input
P0223	Throttle / Pedal Position Sensor / Switch "B" Circuit High Input
P2135	Throttle / Pedal Position Sensor / Switch "A" / "B" Voltage Correlation

DESCRIPTION

Tech Tips

These DTCs relate to the throttle position sensor.

The throttle position sensor is mounted on the throttle body assembly, and detects the opening angle of the throttle valve. This sensor is a non-contact type sensor. It 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 throttle position sensor has 2 sensor circuits, VTA1 and VTA2 each of which transmits a signal. 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 VTA1 and VTA2 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.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
P0120	Throttle / Pedal Position Sensor / Switch "A" Circuit Malfunction	The output voltage of VTA1 quickly fluctuates beyond the lower and upper malfunction thresholds for 2 seconds or more (1 trip detection logic).	Throttle position sensor (built into throttle body assembly) ECM	Comes on	DTC stored
P0121	Throttle / Pedal Position Sensor / Switch "A" Circuit Range / Performance Problem	The difference between the VTA1 and VTA2 voltages is less than 0.8 V, or higher than 1.6 V for 2 seconds (1 trip detection logic).	Throttle position sensor (built into throttle body assembly) Throttle position sensor circuit ECM	Comes on	DTC stored
P0122	Throttle / Pedal Position Sensor / Switch "A" Circuit Low Input	The output voltage of VTA1 is 0.2 V or less for 2 seconds or more (1 trip detection logic).	Throttle position sensor (built into throttle body assembly) Short in VTA1 circuit Open in VCTA circuit ECM	Comes on	DTC stored
P0123	Throttle / Pedal Position Sensor / Switch "A" Circuit High Input	The output voltage of VTA1 is 4.54 V or higher for 2 seconds or more (1 trip detection logic).	Throttle position sensor (built into throttle body assembly) Open in VTA1 circuit Open in ETA circuit Short between VCTA and VTA1 circuits ECM	Comes on	DTC stored
P0220	Throttle / Pedal Position Sensor / Switch "B" Circuit	The output voltage of VTA2 quickly fluctuates beyond the lower and upper malfunction thresholds for 2 seconds or more (1 trip detection logic).	Throttle position sensor (built into throttle body assembly) ECM	Comes on	DTC stored
P0222	Throttle / Pedal Position Sensor / Switch "B" Circuit Low Input	The output voltage of VTA2 is 1.75 V or less for 2 seconds or more (1 trip detection logic).	Throttle position sensor (built into throttle body assembly) Short in VTA2 circuit Open in VCTA circuit ECM	Comes on	DTC stored
P0223	Throttle / Pedal Position Sensor / Switch "B" Circuit High Input	The output voltage of VTA2 is 4.8 V or higher, and VTA1 is between 0.2 V and 2.02 V for 2 seconds or more (1 trip detection logic).	Throttle position sensor (built into throttle body assembly) Open in VTA2 circuit Open in ETA circuit Short between VCTA and VTA2 circuits ECM	Comes on	DTC stored
P2135	Throttle / Pedal Position Sensor / Switch "A" / "B" Voltage Correlation	Either of the following conditions is met (1 trip detection logic): (a) The difference between the output voltages of VTA1 and VTA2 is 0.02 V or less for 0.5 seconds or more. (b) The 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 Throttle position sensor (built into throttle body assembly) ECM	Comes on	DTC stored

MONITOR DESCRIPTION

The ECM uses the throttle position sensor to monitor the throttle valve opening angle. There are several checks that the ECM performs to confirm the proper operation of the throttle position sensor.

P0120, P0122, P0123, P0220, P0222, P0223 and P2135:

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 circuit, 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 circuit, 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 circuit, and stores a DTC.

P0121:

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 throttle position 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 in the throttle position sensor. The ECM illuminates the MIL and stores the DTC.

MONITOR STRATEGY

Frequency of Operation

Continuous

CONFIRMATION DRIVING PATTERN

Connect the GTS to the DLC3.
Turn the power switch on (IG) and turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the power switch off and wait for at least 30 seconds.
Turn the power switch on (IG) and turn the GTS on [A].
Put the engine in inspection mode (maintenance mode).

Click here
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 the pending DTCs.
Tech Tips
- 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: P0120, P0121, P0122, P0123, P0220, P0222, P0223 or P2135.

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

Tech Tips

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 [D] again.

FAIL-SAFE

When any of these DTCs or other DTCs relating to Electronic Throttle Control System (ETCS) malfunctions are stored, the ECM enters fail-safe mode. During fail-safe mode, the ECM cuts the current to the throttle actuator, and the throttle valve is returned to a 5.5° throttle angle by the return spring. The ECM stops the engine and the vehicle can be driven using solely the hybrid system. 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 power switch is then turned off.

WIRING DIAGRAM


*a	Throttle Position Sensor (Built into Throttle Body Assembly)

CAUTION / NOTICE / HINT

Tech Tips

DTC P0121 is stored when the voltages output from VTA1 and VTA2 are not consistent with the characteristics of the sensors. Therefore, check the Freeze Frame Data when this DTC is output. Use the following formula to confirm relative fluctuations 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

Read freeze frame data using the GTS. 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.

PROCEDURE

CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)

Disconnect the throttle body assembly connector.
Disconnect the ECM connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
B25-5 (VC) - B178-115 (VCTA)	Always	Below 1 Ω
B25-6 (VTA) - B178-84 (VTA1)	Always	Below 1 Ω
B25-4 (VTA2) - B178-83 (VTA2)	Always	Below 1 Ω
B25-3 (E2) - B178-116 (ETA)	Always	Below 1 Ω
B25-5 (VC) or B178-115 (VCTA) - Body ground	Always	10 kΩ or higher
B25-6 (VTA) or B178-84 (VTA1) - Body ground	Always	10 kΩ or higher
B25-4 (VTA2) or B178-83 (VTA2) - Body ground	Always	10 kΩ or higher

Result

Proceed to
OK
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

INSPECT ECM (VC VOLTAGE)

*a
Front view of wire harness connector

(to Throttle Body Assembly)

Disconnect the throttle body assembly connector.
Turn the power switch on (IG).

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

Standard Voltage

Tester Connection	Condition	Specified Condition
B25-5 (VC) - B25-3 (E2)	Power switch on (IG)	4.5 to 5.5 V

Result

Proceed to
OK
NG

REPLACE ECM Click here

REPLACE THROTTLE BODY ASSEMBLY

Replace the throttle body assembly.

Click here

Result

Proceed to
NEXT

CHECK WHETHER DTC OUTPUT RECURS (THROTTLE POSITION SENSOR DTCS)

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs
Turn the power switch off and wait for at least 30 seconds.
Turn the power switch on (IG).
Turn the GTS on.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Read the DTCs.

Click here

Powertrain > Engine and ECT > Trouble Codes

Result

Result	Proceed to
DTC P0120, P0121, P0122, P0123, P0220, P0222, P0223 and/or P2135 are output	A
DTC is not output	B

REPLACE ECM Click here

END