Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001GHAW
Model Year Start: 2020 Model: Corolla Prod Date Range: [01/2019 - 03/2019]
Title: 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: P2120-P2123,P2125,P2127,P2128,P2138; Throttle / Pedal Position Sensor / Switch "D" Circuit; 2020 MY Corolla [01/2019 - 03/2019]

DTC

P2120

Throttle / Pedal Position Sensor / Switch "D" Circuit

DTC

P2121

Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance

DTC

P2122

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

DTC

P2123

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

DTC

P2125

Throttle / Pedal Position Sensor / Switch "E" Circuit

DTC

P2127

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

DTC

P2128

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

DTC

P2138

Throttle / Pedal Position Sensor / Switch "D" / "E" Voltage Correlation

DESCRIPTION

HINT:

These DTCs relate to the accelerator pedal position sensor.

The accelerator pedal position sensor is built into the accelerator pedal sensor assembly and has 2 sensor circuits: VPA (main) and VPA2 (sub). This sensor is a non-contact type sensor 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 voltage, which is applied to terminals VPA and VPA2 of the ECM, varies between 0.5 V and 4.75 V in proportion to the operating angle of the accelerator pedal (throttle valve). A signal from VPA indicates the actual accelerator pedal opening angle (throttle valve opening angle) and is used for engine control. A signal from VPA2 conveys the status of the VPA circuit and is used to check the accelerator pedal position sensor itself.

The ECM monitors the actual accelerator pedal opening angle (throttle valve opening angle) through the signals from VPA and VPA2, and controls the throttle actuator according to these signals.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P2120

Throttle / Pedal Position Sensor / Switch "D" Circuit

VPA fluctuates rapidly beyond the upper and lower malfunction thresholds for 0.5 seconds or more (1 trip detection logic).
  • Accelerator pedal sensor assembly
  • Open or short in accelerator pedal sensor assembly circuit
  • ECM

Comes on

DTC stored

P2121

Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance

Either of the following conditions is met (1 trip detection logic):

  1. Difference between VPA and VPA2 is less than 0.4 V, or higher than 1.2 V. (learned value of accelerator off position)
  2. Difference between VPA and VPA2 is greater than or equal to the specified value.
  • Accelerator pedal sensor assembly
  • ECM

Comes on

DTC stored

P2122

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

VPA is 0.4 V or less for 0.5 seconds or more when the accelerator pedal is depressed (1 trip detection logic).
  • Accelerator pedal sensor assembly
  • Open in VCPA circuit
  • Open or ground short in VPA circuit
  • ECM

Comes on

DTC stored

P2123

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

VPA is 4.8 V or higher for 2.0 seconds or more (1 trip detection logic).
  • Accelerator pedal sensor assembly
  • Open in EPA circuit
  • Short in VPA circuit
  • ECM

Comes on

DTC stored

P2125

Throttle / Pedal Position Sensor / Switch "E" Circuit

VPA2 fluctuates rapidly beyond the upper and lower malfunction thresholds for 0.5 seconds or more (1 trip detection logic).
  • Accelerator pedal sensor assembly
  • Open or short in accelerator pedal sensor assembly circuit
  • ECM

Comes on

DTC stored

P2127

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

VPA2 is 1.2 V or less for 0.5 seconds or more when the accelerator pedal is depressed (1 trip detection logic).
  • Accelerator pedal sensor assembly
  • Open in VCP2 circuit
  • Open or ground short in VPA2 circuit
  • ECM

Comes on

DTC stored

P2128

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

Both of the following conditions continue for 2.0 seconds or more (1 trip detection logic):

(a) VPA2 is 4.8 V or higher.

(b) VPA is between 0.4 V and 3.45 V.
  • Accelerator pedal sensor assembly
  • Open in EPA2 circuit
  • Short in VPA2 circuit
  • ECM

Comes on

DTC stored

P2138

Throttle / Pedal Position Sensor / Switch "D" / "E" Voltage Correlation

Either of the following conditions continues for 2.0 seconds or more (1 trip detection logic):

(a) The difference between VPA and VPA2 is 0.02 V or less.

(b) VPA is 0.4 V or less, and VPA2 is 1.2 V or less.
  • Short between VPA and VPA2 circuits
  • Accelerator pedal sensor assembly
  • ECM

Comes on

DTC stored

HINT:

When any of these DTCs are output, check the accelerator pedal position sensor voltage using the Techstream. Enter the following menus: Powertrain / Engine and ECT / Data List / Accel Sensor Out No.1 and Accel Sensor Out No.2.

Trouble Area

Accelerator Pedal Fully Released

Accelerator Pedal Fully Depressed

Accel Sensor Out No.1

Accel Sensor Out No.2

Accel Sensor Out No.1

Accel Sensor Out No.2

Open in VCP circuit

0 to 0.2 V

0 to 0.2 V

0 to 0.2 V

0 to 0.2 V

Open or ground short in VPA circuit

0 to 0.2 V

1.2 to 2.0 V

0 to 0.2 V

3.4 to 4.75 V

Open or ground short in VPA2 circuit

0.5 to 1.1 V

0 to 0.2 V

2.6 to 4.5 V

0 to 0.2 V

Open in EPA circuit

4.5 to 4.98 V

4.5 to 4.98 V

4.5 to 4.98 V

4.5 to 4.98 V

Normal condition

0.5 to 1.1 V

1.2 to 2.0 V

2.6 to 4.5 V

3.4 to 4.75 V

HINT:

Accelerator pedal positions are expressed as voltages.

MONITOR DESCRIPTION

When either output voltage of VPA or VPA2 deviates from the standard range, or the difference between the output voltages of the 2 sensor circuits is more than the threshold, the ECM determines that there is a malfunction in the accelerator pedal position sensor. The ECM then illuminates the MIL and stores a DTC.

Example:

When the output voltage of VPA is 0.4 V or less for 0.5 seconds or more when the accelerator pedal is fully depressed, DTC P2122 is stored.

MONITOR STRATEGY

Related DTCs

P2120: Accelerator pedal position sensor 1 range check (chattering)

P2121: Accelerator pedal position sensor rationality

P2122: Accelerator pedal position sensor 1 range check (low voltage)

P2123: Accelerator pedal position sensor 1 range check (high voltage)

P2125: Accelerator pedal position sensor 2 range check (chattering)

P2127: Accelerator pedal position sensor 2 range check (low voltage)

P2128: Accelerator pedal position sensor 2 range check (high voltage)

P2138: Accelerator pedal position sensor range check (correlation)

Required Sensors/Components (Main)

Accelerator pedal sensor assembly

Required Sensors/Components (Related)

-

Frequency of Operation

Continuous

Duration

0.5 seconds: P2120, P2121 (Case 2), P2122, P2125 and P2127

2.0 seconds: P2123, P2128 and P2138

-: P2121 (Case 1)

MIL Operation

Immediate

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

P2120, P2122, P2123, P2125, P2127, P2128 and P2138

Monitor runs whenever the following DTCs are not stored

None

Either of the following conditions is met

A or B

A. Time after ignition switch off to ON

0.012 seconds or more

B. Command to electronic throttle actuator power

On

P2121

All of the following conditions is met

-

Either of the following conditions is met

A or B

A. Time after ignition switch off to ON

0.012 seconds or more

B. Command to electronic throttle actuator power

On

Accelerator pedal position sensor circuit fail (P2120, P2122, P2123, P2125, P2127, P2128, P2138)

Not detected

TYPICAL MALFUNCTION THRESHOLDS

P2120

Either of the following conditions is met

1 or 2

1. Both of the following conditions are met

-

VPA voltage

0.4 V or less

VPA2 voltage - Learned VPA2 accelerator off position voltage

0.04 V or higher

2. VPA voltage

4.8 V or higher

P2121 (Case 1)

Difference between VPA voltage and VPA2 voltage (learned value of accelerator off position)

Less than 0.4 V, or higher than 1.2 V

P2121 (Case 2)

All of the following conditions are met

-

[(VPA voltage - Learned VPA accelerator off position voltage) - (VPA2 voltage - Learned VPA2 accelerator off position voltage)]

0.165 V or higher (varies with accelerator position)

VPA2 voltage

Less than 4.84 V

Either of the following conditions met

a or b

a) VPA voltage - Learned VPA accelerator off position voltage

0.04 V or higher

b) VPA2 voltage - Learned VPA2 accelerator off position voltage

0.04 V or higher

P2122

Both of the following conditions are met

-

VPA voltage

0.4 V or less

VPA2 voltage - Learned VPA2 accelerator off position voltage

0.04 V or higher

P2123

VPA voltage

4.8 V or higher

P2125

Either of the following conditions is met

1 or 2

1. Both of the following conditions are met

-

VPA2 voltage

1.2 V or less

VPA voltage - Learned VPA accelerator off position voltage

0.04 V or higher

2. VPA2 voltage when VPA voltage 0.4 to 3.45 V

4.8 V or higher

P2127

Both of the following conditions are met

-

VPA2 voltage

1.2 V or less

VPA voltage - Learned VPA accelerator off position voltage

0.04 V or higher

P2128

VPA2 voltage when VPA voltage 0.4 to 3.45 V

4.8 V or higher

P2138

Either of the following conditions is met

A or B

A. Difference between VPA and VPA2 voltages

0.02 V or less

B. Both of the following conditions are met

-

VPA voltage

0.4 V or less

VPA2 voltage

1.2 V or less

COMPONENT OPERATING RANGE

All of the following conditions are met

-

VPA voltage

Higher than 0.4 V, and less than 4.8 V

VPA2 voltage

Higher than 1.2 V, and less than 4.8 V

Difference between VPA and VPA2 voltages

Higher than 0.02 V

CONFIRMATION DRIVING PATTERN

P2120, P2122, P2123, P2125, P2127, P2128, P2138

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON.
  3. Turn the Techstream on.
  4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  5. Turn the ignition switch off and wait for at least 30 seconds.
  6. Turn the ignition switch to ON [A].
  7. Turn the Techstream on.
  8. Fully depress and release the accelerator pedal [B].
  9. Check that 5 seconds or more have elapsed since the ignition switch is turned to ON.
  10. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].
  11. Read the pending DTCs.

    HINT:

    • If a pending DTC is output, the system is malfunctioning.
    • If a pending DTC is not output, perform the following procedure.
  12. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  13. Input the DTC: P2120, P2122, P2123, P2125, P2127, P2128 or P2138.
  14. 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 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 [C] again.
  15. If no pending DTC is output, perform a universal trip and check for permanent DTCs.

    Click here 2020 MY Corolla [01/2019 - 03/2019]; 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

    HINT:

    • If a permanent DTC is output, the system is malfunctioning.
    • If no permanent DTC is output, the system is normal.

P2121

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON.
  3. Turn the Techstream on.
  4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  5. Turn the ignition switch off and wait for at least 30 seconds.
  6. Turn the ignition switch to ON [A].
  7. Turn the Techstream on.
  8. Wait for 5 seconds after turning the ignition switch turned to ON.
  9. Operate the accelerator pedal in accordance with the following procedure [B].
    1. Enter the following menus: Powertrain / Engine and ECT / Data List / Accel Sens. No.1 Volt %, and Accel Sens. No.2 Volt %.
    2. Slowly depress the accelerator pedal until Accel Sens. No.1 Volt % is approximately 30% and Accel Sens. No.2 Volt % is approximately 46%, then slowly release the accelerator pedal.
  10. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].
  11. Read the pending DTCs.

    HINT:

    • If a pending DTC is output, the system is malfunctioning.
    • If a pending DTC is not output, perform the following procedure.
  12. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  13. Input the DTC: P2121.
  14. 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 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 [C] again.
  15. If no pending DTC is output, perform a universal trip and check for permanent DTCs.

    Click here 2020 MY Corolla [01/2019 - 03/2019]; 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

    HINT:

    • If a permanent DTC is output, the system is malfunctioning.
    • If no permanent DTC is output, the system is normal.

FAIL-SAFE

When these DTCs are stored, the ECM enters fail-safe mode. If either of the 2 sensor circuits malfunctions, the ECM limits the engine output. If both of the circuits malfunction, the ECM regards the accelerator pedal as being released. As a result, the throttle valve is closed and the engine idles.

Fail-safe mode continues until a pass condition is detected, and the ignition switch is turned off.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

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

1.

READ VALUE USING TECHSTREAM (ACCEL SENSOR OUT NO. 1 AND NO. 2)

(a) Connect the Techstream to the DLC3.

*a

Fully Depressed

*b

Fully Released

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Accel Sensor Out No.1 and Accel Sensor Out No.2.

Powertrain > Engine and ECT > Data List

Tester Display

Accel Sensor Out No.1

Accel Sensor Out No.2

(e) Read the value displayed on the Techstream.

Standard Voltage:

Accelerator Pedal Operation

Accel Sensor Out No.1

Accel Sensor Out No.2

Difference between Accel Sensor Out No.1 and Accel Sensor Out No.2

Fully Released

0.5 to 1.1 V

1.2 to 2.0 V

More than 0.02 V

Fully Depressed

2.6 to 4.5 V

3.4 to 4.75 V
OK

CHECK FOR INTERMITTENT PROBLEMS

NG

2.

CHECK TERMINAL VOLTAGE (POWER SOURCE OF ACCELERATOR PEDAL SENSOR ASSEMBLY)

*a

Front view of wire harness connector

(to Accelerator Pedal Sensor Assembly)

HINT:

Make sure that the connector is properly connected. If it is not, securely connect it and check for DTCs again.

(a) Disconnect the accelerator pedal sensor assembly 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

Condition

Specified Condition

A54-4 (VCPA) - A54-5 (EPA)

Ignition switch ON

4.5 to 5.5 V

A54-1 (VCP2) - A54-2 (EPA2)

Ignition switch ON

4.5 to 5.5 V
NG

GO TO STEP 5

OK

3.

CHECK HARNESS AND CONNECTOR (RESISTANCE OF ECM)

*a

Front view of wire harness connector

(to Accelerator Pedal Sensor Assembly)

(a) Disconnect the accelerator pedal sensor assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A54-6 (VPA) - A54-5 (EPA)

Ignition switch off

37.05 to 40.95 kΩ

A54-3 (VPA2) - A54-2 (EPA2)

Ignition switch off

37.05 to 40.95 kΩ
OK

REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY

NG

4.

CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL SENSOR ASSEMBLY - ECM)

(a) Disconnect the accelerator pedal sensor assembly 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

A54-6 (VPA) - A46-47 (VPA)

Always

Below 1 Ω

A54-5 (EPA) - A46-48 (EPA)

Always

Below 1 Ω

A54-3 (VPA2) - A46-50 (VPA2)

Always

Below 1 Ω

A54-2 (EPA2) - A46-51 (EPA2)

Always

Below 1 Ω

A54-6 (VPA) or A46-47 (VPA) - Body ground and other terminals

Always

10 kΩ or higher

A54-5 (EPA) or A46-48 (EPA) - Body ground and other terminals

Always

10 kΩ or higher

A54-3 (VPA2) or A54-50 (VPA2) - Body ground and other terminals

Always

10 kΩ or higher

A54-2 (EPA2) or A46-51 (EPA2) - Body ground and other terminals

Always

10 kΩ or higher
OK

REPLACE ECM

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.

CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL SENSOR ASSEMBLY - ECM)

(a) Disconnect the accelerator pedal sensor assembly 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

A54-4 (VCPA) - A46-49 (VCPA)

Always

Below 1 Ω

A54-5 (EPA) - A46-48 (EPA)

Always

Below 1 Ω

A54-1 (VCP2) - A46-52 (VCP2)

Always

Below 1 Ω

A54-2 (EPA2) - A46-51 (EPA2)

Always

Below 1 Ω

A54-4 (VCPA) or A46-49 (VCPA) - Body ground and other terminals

Always

10 kΩ or higher

A54-5 (EPA) or A46-48 (EPA) - Body ground and other terminals

Always

10 kΩ or higher

A54-1 (VCP2) or A46-52 (VCP2) - Body ground and other terminals

Always

10 kΩ or higher

A54-2 (EPA2) or A46-51 (EPA2) - Body ground and other terminals

Always

10 kΩ or higher
OK

REPLACE ECM

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR