Last Modified: 11-29-2007 1.6 C
Service Category: Engine/Hybrid System Section: Engine Control
Model Year: 2008 Model: Sequoia Doc ID: RM000000PF605TX
Title: 3UR-FE ENGINE CONTROL: SFI SYSTEM: CAUTION / NOTICE / HINT (2008 Sequoia)

DTC

P0120

Throttle / Pedal Position Sensor / Switch "A" Circuit Malfunction

DTC

P0122

Throttle / Pedal Position Sensor / Switch "A" Circuit Low Input

DTC

P0123

Throttle / Pedal Position Sensor / Switch "A" Circuit High Input

DTC

P0220

Throttle / Pedal Position Sensor / Switch "B" Circuit

DTC

P0222

Throttle / Pedal Position Sensor / Switch "B" Circuit Low Input

DTC

P0223

Throttle / Pedal Position Sensor / Switch "B" Circuit High Input

DTC

P2135

Throttle / Pedal Position Sensor / Switch "A" / "B" Voltage Correlation

CAUTION / NOTICE / HINT

DESCRIPTION

The TP sensor is mounted on the throttle body, and detects the opening angle of the throttle valve. This sensor is a non-contact type. 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 TP 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 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.



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 Position (TP) sensor (built into throttle body)
  • ECM

P0122

Output voltage of VTA1 0.2 V or less for 2 seconds when accelerator pedal depressed

(1 trip detection logic)
  • TP sensor (built into throttle body)
  • 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)
  • 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 when accelerator pedal depressed

(1 trip detection logic)
  • TP sensor (built into throttle body)
  • ECM

P0222

Output voltage of VTA2 1.75 V or less for 2 seconds when accelerator pedal depressed

(1 trip detection logic)
  • TP sensor (built into throttle body)
  • 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)
  • 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) 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
  • TP sensor (built into throttle body)
  • ECM

HINT:

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

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

    Reference (Normal Condition):

    Tester Display

    Accelerator Pedal Fully Released

    Accelerator Pedal Fully Depressed

    Throttle Position No. 1

    0.5 to 1.1 V

    3.3 to 4.9 V

    Throttle Position No. 2

    2.1 to 3.1 V

    4.6 to 5.0 V

MONITOR DESCRIPTION

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.

MONITOR STRATEGY

Related DTCs

P0120: Throttle position sensor 1 range check (Fluctuating)

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 (Accelerator pedal ON)

10 seconds: P0120, P0122, P0123, P0220, P0222 and P0223 (Accelerator pedal OFF)

0.5 seconds: P2135 Case 1

0.4 seconds: P2135 Case 2

MIL Operation

Immediate

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

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

TYPICAL MALFUNCTION THRESHOLDS

P0120

VTA1 voltage

0.2 V or less, or 4.535 V or more

P0122

VTA1 voltage

0.2 V or less

P0123

VTA1 voltage

4.535 V or more

P0220

VTA2 voltage

1.75 V or less, or 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

FAIL-SAFE

When any of these DTCs, as well as 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 the current to the throttle actuator, and the throttle valve is returned to a 7° 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

INSPECTION PROCEDURE

HINT:

  • These DTCs relate to the Throttle Position (TP) sensor.
  • Read freeze frame data using the Techstream. Freeze frame data records the engine condition when malfunctions are detected. 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

1.

READ VALUE USING TECHSTREAM (THROTTLE POSITION)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

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

(e) Check the values displayed on the Techstream.

Result

TP#1 (VTA1)

When Accelerator Pedal Released

TP#2 (VTA2)

When Accelerator Pedal Released

TP#1 (VTA1)

When Accelerator Pedal Depressed

TP#2 (VTA2)

When Accelerator Pedal Depressed

Trouble Area

Proceed to

0 to 0.2 V

0 to 0.2 V

0 to 0.2 V

0 to 0.2 V

VC circuit open

A

4.5 to 5.0 V

4.5 to 5.0 V

4.5 to 5.0 V

4.5 to 5.0 V

E2 circuit open

A

0 to 0.2 V,

or 4.5 to 5.0 V

2.4 to 3.4 V

(Fail-safe)

0 to 0.2 V,

or 4.5 to 5.0 V

2.4 to 3.4 V

(Fail-safe)

VTA1 circuit open or ground short

A

0.7 to 1.3 V

(Fail-safe)

0 to 0.2 V,

or 4.5 to 5.0 V

0.7 to 1.3 V

(Fail-safe)

0 to 0.2 V,

or 4.5 to 5.0 V

VTA2 circuit open or ground short

A

0.5 to 1.1 V

2.1 to 3.1 V

3.3 to 4.9 V

(Not fail-safe)

4.6 to 5.0 V

(Not fail-safe)

TP sensor circuit normal

B

HINT:

TP#1 stands for Throttle Position No. 1, and TP#2 stands for Throttle Position No. 2.

A

2.

CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)


(a) Disconnect the throttle body connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

D4-5 (VC) - D56-80 (VCTA)

Always

Below 1 Ω

D4-6 (VTA) - D56-78 (VTA1)

Always

Below 1 Ω

D4-4 (VTA2) - D56-77 (VTA2)

Always

Below 1 Ω

D4-3 (E2) - D56-79 (ETA)

Always

Below 1 Ω

D4-5 (VC) or D56-80 (VCTA) - Body ground

Always

10 kΩ or higher

D4-6 (VTA) or D56-78 (VTA1) - Body ground

Always

10 kΩ or higher

D4-4 (VTA2) or D56-77 (VTA2) - Body ground

Always

10 kΩ or higher
OK

3.

INSPECT ECM (VC VOLTAGE)


(a) Disconnect the throttle body connector.

(b) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

D4-5 (VC) - D4-3 (E2)

Ignition switch ON

4.5 to 5.5 V
OK

4.

REPLACE THROTTLE BODY ASSEMBLY

(a) Replace the throttle body assembly 3UR-FE ENGINE CONTROL: THROTTLE BODY: REMOVAL (2008 Sequoia) .

NEXT

5.

CHECK WHETHER DTC OUTPUT RECURS (THROTTLE POSITION SENSOR DTCS)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Clear DTCs 3UR-FE ENGINE CONTROL: SFI SYSTEM: DTC CHECK / CLEAR (2008 Sequoia) .

(e) Start the engine.

(f) Allow the engine to idle for 15 seconds or more.

(g) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(h) Read DTCs.

Result

Result

Proceed to

P0120, P0122, P0123, P0220, P0222, P0223 and/or P2135 are output

A

No DTC is output

B
A