2GR-FE (ENGINE CONTROL): SFI SYSTEM: P0120-P0123,P0220,P0222,P0223,P2135; Throttle / Pedal Position Sensor / Switch "A" Circuit; 2016 MY Sienna [12/2015

The throttle position sensor is mounted on the throttle body with motor 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, each of which 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 VTA1 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.

Throttle Position No. 1 is the VTA1 signal, and Throttle Position No. 2 is 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 4.98 V

MONITOR DESCRIPTION

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

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.

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.

If the malfunction is not repaired successfully, a DTC is stored 10 seconds after the engine is next started.

P0121

This sensor transmits 2 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 2 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.

If the malfunction is not repaired successfully, the DTC is stored 2 seconds after the engine is next started.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

P0120, P0122, P0123, P0220, P0222, P0223, P02135

P0121

TYPICAL MALFUNCTION THRESHOLDS

P0120

P0121

P0122

P0123

P0220

P0222

P0223

P2135 Case 1

P2135 Case 2

COMPONENT OPERATING RANGE

CONFIRMATION DRIVING PATTERN

Connect the Techstream to the DLC3.
Turn the ignition switch to ON and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) (See page ).
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 / Trouble Codes [D].
Read 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 / 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 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 (See page ).
HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

FAIL-SAFE

When any of these DTCs or other DTCs relating to electronic throttle control system 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 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 off.

WIRING DIAGRAM

CAUTION / NOTICE / 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.

PROCEDURE

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

Result

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.
Calculate the voltage of VTA1 and VTA2 according to Throttle Sensor Volt % and Throttle Sensor #2 Volt % respectively and confirm their consistency.

Example:

Throttle Sensor Volt % / 100 (%) x 5 (V) = Throttle Position No.1

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 Position Sensor - ECM)".

Text in Illustration

Perform "Inspection After Repair" after repairing the throttle body with motor assembly (See page

2016 MY Sienna [12/2015 - 08/2016]; 2GR-FE (ENGINE CONTROL): SFI SYSTEM: SYSTEM DIAGRAM

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