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

This ETCS (Electronic Throttle Control System) does not use a throttle cable.

The Throttle Position (TP) sensor is mounted on the throttle body, 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, 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.

A000USHE02
DTC No. DTC Detection Condition Trouble Area
P0120

Output voltage of VTA1 quickly fluctuates beyond lower and upper malfunction thresholds for 2 seconds

(1 trip detection logic)


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

  • ECM

P0121

Difference between VTA and VTA2 voltages less than 0.8 V, or more than 1.6 V for 2 seconds

(1 trip detection logic)


  • TP sensor (built into throttle body)

  • TP sensor circuit

  • ECM

P0122

Output voltage of VTA1 0.2 V or less for 2 seconds

(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

(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

(1 trip detection logic)


  • TP sensor (built into throttle body)

  • ECM

P0222

Output voltage of VTA2 1.75 V or less for 2 seconds

(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 (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) is 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

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.


FAIL-SAFE

When any of these DTCs, as well as other DTCs relating to ETCS (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 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 power switch is then turned off.

WIRING DIAGRAM

A000UYSE04
*a Throttle Position Sensor

CAUTION / NOTICE / HINT

Tech Tips


  • If other DTCs relating to different systems that have terminal ETA as the ground terminal are output simultaneously, terminal ETA may have an open circuit.

  • Read freeze frame data using the intelligent tester. 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. CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)


    1. Disconnect the E21 throttle body connector.

      A000W75E04
      *1 Front view of wire harness connector: (to Throttle Position Sensor)
      *2 Rear view of wire harness connector: (to ECM)
    2. Disconnect the E2 ECM connector.

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

      Standard resistance (Check for open)
      Tester Connection Condition Specified Condition
      E21-5 (VC) - E2-34 (VCTA) Always Below 1 Ω
      E21-6 (VTA) - E2-26 (VTA1) Always Below 1 Ω
      E21-4 (VTA2) - E2-27 (VTA2) Always Below 1 Ω
      E21-3 (E2) - E2-35 (ETA) Always Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Condition Specified Condition
      E21-5 (VC) or E2-34 (VCTA)- Body ground Always 10 kΩ or higher
      E21-6 (VTA) or E2-26 (VTA1) - Body ground Always 10 kΩ or higher
      E21-4 (VTA2) or E2-27 (VTA2) - Body ground Always 10 kΩ or higher

    NG
    OK
  2. INSPECT ECM (VC VOLTAGE)


    1. A000YXVE01
      *1 Front view of wire harness connector: (to Throttle Body)

      Disconnect the E21 throttle body connector.

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      E21-5 (VC) - E21-3 (E2) Power switch on (IG) 4.5 to 5.0 V

    NG
    OK
  3. REPLACE THROTTLE BODY


    1. Replace the throttle body Click here.


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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester ON.

    4. Clear DTCs Click here.

    5. Turn the power switch off and wait for at least 30 seconds.

    6. Turn the power switch on (IG) and turn the intelligent tester ON.

    7. Put the engine in inspection mode Click here.

    8. Allow the engine to idle for 15 seconds or more.

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

    10. Read DTCs.

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

    A
    B