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Home >> Toyota >> 2014 >> Corolla LE Eco Plus >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 17 (Engine Control System (2ZR-FE) - Diagnostic Codes (4 Of 7) (Model Code: ZRE172)) >> SFI System >> DTC P2120, P2122, P2123, P2125, P2127, P2128, P2138; Throttle / Pedal Position Sensor / Switch "D" Circuit [08/2016 - ] >> Description
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DTC P2120, P2122, P2123, P2125, P2127, P2128, P2138; Throttle / Pedal Position Sensor / Switch "D" Circuit [08/2016 - ]: Description

WARNING: This page is about a different variant/trim than selected.

HINT: 

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.

GTY438281Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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
  • 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
  • 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
  • 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
  • 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 / Gas Throttle / 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.