SFI SYSTEM (w/o Secondary Air Injection System), Diagnostic DTC:P2120/19, P2122/19, P2123/19, P2125/19, P2127/19, P2128/19, P2138/19

DTC Code	DTC Name
P2120/19	Throttle / Pedal Position Sensor / Switch "D" Circuit
P2122/19	Throttle / Pedal Position Sensor / Switch "D" Circuit Low Input
P2123/19	Throttle / Pedal Position Sensor / Switch "D" Circuit High Input
P2125/19	Throttle / Pedal Position Sensor / Switch "E" Circuit
P2127/19	Throttle / Pedal Position Sensor / Switch "E" Circuit Low Input
P2128/19	Throttle / Pedal Position Sensor / Switch "E" Circuit High Input
P2138/19	Throttle / Pedal Position Sensor / Switch "D" / "E" Voltage Correlation

DESCRIPTION

Tech Tips

These DTCs relate to the Accelerator Pedal Position (APP) sensor.
This ETCS (Electronic Throttle Control System) does not use a throttle cable.

The Accelerator Pedal Position (APP) sensor is mounted on the accelerator pedal bracket and has 2 sensor circuits: VPA (main) and VPA2 (sub). 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 voltage, which is applied to terminals VPA and VPA2 of the ECM, varies between 0 V and 5 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 APP 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.	DTC Detection Conditions	Trouble Areas
P2120/19	VPA fluctuates rapidly beyond upper and lower malfunction thresholds for 0.5 seconds or more (1 trip detection logic)	Accelerator Pedal Position (APP) sensor ECM
P2122/19	VPA 0.2 V or less for 0.5 seconds or more when accelerator pedal fully released (1 trip detection logic)	APP sensor Open in VCP1 circuit Open or ground short in VPA circuit ECM
P2123/19	VPA 4.8 V or more for 2.0 seconds or more (1 trip detection logic)	APP sensor Open in EPA circuit ECM
P2125/19	VPA2 fluctuates rapidly beyond upper and lower malfunction thresholds for 0.5 seconds or more (1 trip detection logic)	APP sensor ECM
P2127/19	VPA2 0.5 V or less for 0.5 seconds or more when accelerator pedal fully released (1 trip detection logic)	APP sensor Open in VCP2 circuit Open or ground short in VPA2 circuit ECM
P2128/19	Conditions (a) and (b) continue for 2.0 seconds or more (1 trip detection logic): VPA2 4.8 V or more VPA between 0.2 V and 3.45 V	APP sensor Open in EPA2 circuit ECM
P2138/19	Condition (a) or (b) continues for 2.0 seconds or more (1 trip detection logic): Difference between VPA and VPA2 0.02 V or less VPA 0.2 V or less and VPA2 0.5 V or less	Short between VPA and VPA2 circuits APP sensor ECM

Tech Tips

When any of these DTCs are set, check the APP sensor voltage by selecting the following menu items on an intelligent tester: Powertrain / Engine and ECT / Data List / Accel Pos #1 and Accel Pos #2.

Trouble Areas	ACCEL POS #1 When AP Released	ACCEL POS #2 When AP Released	ACCEL POS #1 When AP Depressed	ACCEL POS #2 When AP Depressed
VCP circuit open	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 5.0 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
EPA circuit open	4.5 to 5.0 V	4.5 to 5.0 V	4.5 to 5.0 V	4.5 to 5.0 V
Normal condition	0.5 to 1.1 V	1.2 to 2.0 V	2.6 to 4.5 V	3.4 to 5.0 V

Tech Tips

Accelerator pedal positions are expressed as voltages.
AP denotes for Accelerator Pedal.

MONITOR DESCRIPTION

When either of the voltage outputs of VPA or VPA2 deviates from the standard range, or the difference between the voltage outputs of the 2 sensor circuits is less than the threshold, the ECM determines that there is a malfunction in the APP sensor. The ECM then illuminates the MIL and sets a DTC.

Example:

When the voltage output of VPA drops below 0.2 V for more than 0.5 seconds when the accelerator pedal is fully depressed, DTC P2122 is set.

If the malfunction is not repaired successfully, a DTC is set 2 seconds after the engine is next started.

FAIL-SAFE

When any of DTCs P2120, P2121, P2122, P2123, P2125, P2127, P2128 and P2138 are set, the ECM enters fail-safe mode. If either of the 2 sensor circuits malfunctions, the ECM uses the remaining circuit to calculate the accelerator pedal position to allow the vehicle to continue driving. 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 to OFF.

WIRING DIAGRAM

INSPECTION PROCEDURE

Tech Tips

Read freeze frame data using an 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.

PROCEDURE

READ VALUE USING INTELLIGENT TESTER (ACCEL POS #1 AND ACCEL POS #2)

Connect an intelligent tester to the DLC3.
Turn the ignition switch to the ON position and turn the tester ON.
Select the following menu items: Powertrain / Engine and ECT / Data List / Accel Pos #1 and Accel Pos #2.

Read the values displayed on the tester.

Voltage

Accelerator Pedal Operations

ACCEL POS #1

(AP #1)

ACCEL POS #2

(AP #2)

Released

0.5 to 1.1 V

1.2 to 2.0 V

Depressed

2.6 to 4.5 V

3.4 to 5.0 V

CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL POSITION SENSOR DTCS) Click here

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

Disconnect the B1 Accelerator Pedal Position (APP) sensor connector.
Disconnect the B9 ECM connector.

Measure the resistance.

Resistance (Check for open)

Tester Connections	Specified Conditions
VPA (B1-6) - VPA (B9-18)	Below 1 Ω
EPA (B1-5) - EPA (B9-20)	Below 1 Ω
VCPA (B1-4) - VCPA (B9-26)	Below 1 Ω
VPA2 (B1-3) - VPA2 (B9-19)	Below 1 Ω
EPA2 (B1-2) - EPA2 (B9-21)	Below 1 Ω
VCP2 (B1-1) - VCP2 (B9-27)	Below 1 Ω

Resistance (Check for short)

Tester Connections	Specified Conditions
VPA (B1-6) or VPA (B9-18) - Body ground	10 kΩ or higher
EPA (B1-5) or EPA (B9-20) - Body ground	10 kΩ or higher
VCPA (B1-4) or VCPA (B9-26) - Body ground	10 kΩ or higher
VPA2 (B1-3) or VPA2 (B9-19) - Body ground	10 kΩ or higher
EPA2 (B1-2) or EPA2 (B9-21) - Body ground	10 kΩ or higher
VCP2 (B1-1) or VCP2 (B9-27) - Body ground	10 kΩ or higher

Reconnect the APP sensor connector.
Reconnect the ECM connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR

INSPECT ECM (VCPA AND VCP2 VOLTAGE)

Disconnect the APP sensor connector.
Turn the ignition switch to the ON position.

Measure the voltage between the terminals of the ECM connector.

Voltage

Tester Connections	Specified Conditions
VCPA (B9-26) - EPA (B9-20)	4.5 to 5.0 V
VCP2 (B9-27) - EPA2 (B9-21)	4.5 to 5.0 V

Reconnect the APP sensor connector.

REPLACE ECM

REPLACE ACCELERATOR PEDAL ROD ASSEMBLY

NEXT

CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL POSITION SENSOR DTCS)

Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position and turn the tester ON.
Clear DTCs Click here.
Allow the engine to idle for 15 seconds.
Select the following menu items: Powertrain / Engine and ECT / DTC.

Read DTCs.

Result

Display (DTC Output)	Proceed To
P2120, P2122, P2123, P2125, P2127, P2128 and P2138	A
No output	B

SYSTEM OK

REPLACE ECM