M20A-FKS (ENGINE CONTROL): SFI SYSTEM: P212012; Throttle/Pedal Position Sensor/Switch "D" Circuit Short to Battery; 2019 - 2020 MY Corolla Corolla Hatchback [06/2018

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.

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

MONITOR DESCRIPTION

When the engine switch is on (IG) and the VPA voltage is 4.8 V or higher for 2 seconds or more, the ECM determines that the accelerator pedal sensor assembly circuit is malfunctioning and illuminates the MIL and stores a DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

HINT:

After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
Click here
When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.
Click here

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG) [A].
Turn the Techstream on.
Fully depress and release the accelerator pedal [B].
Check that 5 seconds or more have elapsed since the engine switch on (IG).
Enter the following menus: Powertrain / Engine / Trouble Codes [C].
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.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Proceed to the next screen and enter the DTC to be checked.

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

HINT:

If the judgment result is NORMAL, the system is normal.
If the judgment result is ABNORMAL, the system is malfunctioning.
If the judgment result is INCOMPLETE, perform steps [B] through [C] again.
[A] to [C]: Normal judgment procedure.
The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
When clearing the permanent DTCs, do not disconnect the cable from the battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

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 engine switch is 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

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

If the value differs from standard, there may be a short in the power source circuit.