DTC P0120 P0121 P0122 P0123 P0220 P0222 P0223 P2135 2ZR-FXE

DTC P0120 Throttle / Pedal Position Sensor / Switch "A" Circuit Malfunction

DTC P0121 Throttle / Pedal Position Sensor / Switch "A" Circuit Range / Performance Problem

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

  1. Description

  2. Monitor description

  3. Monitor strategy

  4. Confirmation driving pattern

  5. Fail-safe

  6. Wiring diagram

  7. Inspection procedure

  8. Check harness and connector (throttle position sensor - ecm)

  9. Inspect ecm (vc voltage)

  10. Replace throttle body assembly

  11. Check whether dtc output recurs (throttle position sensor dtcs)

Description

HINT:

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. It uses Hall-effect elements in order to yield accurate signals even in extreme conditions.

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 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 enrichment correction and fuel-cut control.

Lexus DTC P0120 DTC P0121 DTC P0122 DTC P0123 DTC P0220 DTC P0222 DTC P0223 DTC P2135 Description

 

DTC No. DTC Detection Condition Trouble Area
P0120 Output voltage of VTA1 quickly fluctuates beyond lower and upper malfunction thresholds for 2 seconds or more (1 trip detection logic).
  1. Throttle position sensor (built into throttle body assembly)
  1. ECM
P0121 Difference between VTA1 and VTA2 voltages below 0.8 V, or higher than 1.6 V for 2 seconds (1 trip detection logic).
  1. Throttle position sensor (built into throttle body assembly)
  2. Throttle position sensor circuit
  3. ECM
P0122 Output voltage of VTA1 0.2 V or less for 2 seconds or more (1 trip detection logic).
  1. Throttle position sensor (built into throttle body assembly)
  1. Short in VTA1 circuit
  1. Open in VC circuit
  1. ECM
P0123 Output voltage of VTA1 4.54 V or higher for 2 seconds or more (1 trip detection logic).
  1. Throttle position sensor (built into throttle body assembly)
  1. Open in VTA1 circuit
  1. Open in E2 circuit
  1. Short between VC and VTA1 circuits
  1. ECM
P0220 Output voltage of VTA2 quickly fluctuates beyond lower and upper malfunction thresholds for 2 seconds or more (1 trip detection logic).
  1. Throttle position sensor (built into throttle body assembly)
  1. ECM
P0222 Output voltage of VTA2 1.75 V or less for 2 seconds or more (1 trip detection logic).
  1. Throttle position sensor (built into throttle body assembly)
  1. Short in VTA2 circuit
  1. Open in VC circuit
  1. ECM
P0223 Output voltage of VTA2 4.8 V or higher, and VTA1 between 0.2 V and 2.02 V, for 2 seconds or more (1 trip detection logic).
  1. Throttle position sensor (built into throttle body assembly)
  1. Open in VTA2 circuit
  1. Open in E2 circuit
  1. Short between VC and VTA2 circuits
  1. 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 is 0.2 V or less, and VTA2 is 1.75 V or less, for 0.4 seconds or more
  1. Short between VTA1 and VTA2 circuits
  1. Throttle position sensor (built into throttle body assembly)
  1. ECM

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.

  1. P0120, P0122, P0123, P0220, P0222, P0223, P2135
    1. 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 sets a DTC.
    2. 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 sets a DTC.
    3. 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 sets a DTC.
    If the malfunction is not repaired successfully, a DTC is set 10 seconds after the engine is next started.
  1. 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. If the malfunction is not repaired successfully, the DTC is stored 2 seconds after the engine is next started.

Monitor strategy

Frequency of Operation Continuous

Confirmation driving pattern

Lexus DTC P0120 DTC P0121 DTC P0122 DTC P0123 DTC P0220 DTC P0222 DTC P0223 DTC P2135 Confirmation driving pattern
  1. Connect the intelligent tester to the DLC3.
  2. Turn the power switch on (IG) and turn the tester on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).
  4. Turn the power switch off and wait for 30 seconds.
  5. Turn the power switch on (IG) and turn the tester on [A].
  6. Put the engine in inspection mode (maintenance mode) .
  7. Start the engine.
  8. With the vehicle stationary, fully depress and release the accelerator pedal [B].
  9. Idle the engine for 2 seconds or more [C].
  10. Enter the following menus: Powertrain / Engine and ECT / DTC.
  11. Read the DTC [D].

    HINT:

    1. If a DTC is output, the system is malfunctioning.
    2. If a DTC is not output, perform the following procedure.
  12. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  13. Input the DTC: P0120, P0121, P0122, P0123, P0220, P0222, P0223 or P2135.
  14. Check the DTC judgment result.
    Tester Display Description
    NORMAL
    1. DTC judgment completed
    2. System normal
    ABNORMAL
    1. DTC judgment completed
    2. System abnormal
    INCOMPLETE
    1. DTC judgment not completed
    2. Perform driving pattern after confirming DTC enabling conditions
    UNKNOWN
    1. Unable to perform DTC judgment
    2. Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:

    1. If the judgment result shows NORMAL, the system is normal.
    2. If the judgment result shows ABNORMAL, the system has a malfunction.
    3. If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [B] and [C] again.

FAIL-SAFE

When any of these DTCs, as well as other DTCs relating to 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, 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

Lexus DTC P0120 DTC P0121 DTC P0122 DTC P0123 DTC P0220 DTC P0222 DTC P0223 DTC P2135 Wiring diagram

Inspection procedure

HINT:

  1. 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.

    Features of sensor output:

    VTA2 x 0.8 is approximately equal to VTA1 + 1.11 V

    VTA1: Throttle Position No. 1

    VTA2: Throttle position No. 2

  2. 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.

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

  1. Disconnect the throttle body assembly connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance:

    Tester Connection Condition Specified Condition
    D4-5 (VC) - D27-88 (VCTA) Always Below 1 ?
    D4-6 (VTA) - D27-90 (VTA1) Always Below 1 ?
    D4-4 (VTA2) - D27-89 (VTA2) Always Below 1 ?
    D4-3 (E2) - D27-111 (ETA) Always Below 1 ?
    D4-5 (VC) or D27-88 (VCTA) - Body ground Always 10 k? or higher
    D4-6 (VTA) or D27-90 (VTA1) - Body ground Always 10 k? or higher
    D4-4 (VTA2) or D27-89 (VTA2) - Body ground Always 10 k? or higher
  NG  
REPAIR OR REPLACE HARNESS OR CONNECTOR
 
OK  
   

2.INSPECT ECM (VC VOLTAGE)

Lexus DTC P0120 DTC P0121 DTC P0122 DTC P0123 DTC P0220 DTC P0222 DTC P0223 DTC P2135 Disconnect the throttle body assembly connector.

  1. Disconnect the throttle body assembly connector.

  1. Turn the power switch on (IG).

  1. 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) Power switch on (IG) 4.5 to 5.5 V
    Text in Illustration
    *a Front view of wire harness connector (to Throttle Body Assembly)
  NG  
REPLACE ECM
 
OK  
   

3.REPLACE THROTTLE BODY ASSEMBLY

  1. Replace the throttle body assembly .

NEXT  
   

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

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the tester on.

  1. Clear the DTCs .

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

  1. Enter the following menus: Powertrain / Engine and ECT / DTC.

  1. Read the DTCs.

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