P2120, P2121, P2122, P2123, P2125, P2127, P2128, P2138

DTC Code	DTC Name
P2120	Throttle / Pedal Position Sensor / Switch "D" Circuit
P2121	Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance
P2122	Throttle / Pedal Position Sensor / Switch "D" Circuit Low Input
P2123	Throttle / Pedal Position Sensor / Switch "D" Circuit High Input
P2125	Throttle / Pedal Position Sensor / Switch "E" Circuit
P2127	Throttle / Pedal Position Sensor / Switch "E" Circuit Low Input
P2128	Throttle / Pedal Position Sensor / Switch "E" Circuit High Input
P2138	Throttle / Pedal Position Sensor / Switch "D" / "E" Voltage Correlation

DESCRIPTION

Tech Tips

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): Difference between VPA and VPA2 is less than 0.4 V, or higher than 1.2 V. (learned value of accelerator off position) 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 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 are met for 2 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 is met for 2 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

Tech Tips

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

Trouble Area	Accelerator Pedal Fully Released		Accelerator Pedal Fully Depressed
Trouble Area	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

Tech Tips

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

Required Sensors/Components	Accelerator pedal sensor assembly
Frequency of Operation	Continuous

CONFIRMATION DRIVING PATTERN

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

Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON.
Turn the GTS on [A].
Fully depress and release the accelerator pedal [B].
Check that 5 seconds or more have elapsed since the ignition switch is turned to ON.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].
Read the pending DTCs.
Tech Tips
- 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 and ECT / Utility / All Readiness.
Input the DTC: P2120, P2122, P2123, P2125, P2127, P2128 or P2138.

Check the DTC judgment result.

GTS 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

Tech Tips

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] and [C] again.

P2121

Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON.
Turn the GTS on [A].
Wait for 5 seconds after turning the ignition switch turned to ON.
Operate the accelerator pedal in accordance with the following procedure [B].

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Accel Sens. No.1 Volt %, and Accel Sens. No.2 Volt %.
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.

Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].
Read the pending DTCs.
Tech Tips
- 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 and ECT / Utility / All Readiness.
Input the DTC: P2121.

Check the DTC judgment result.

GTS 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

Tech Tips

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] and [C] again.

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


*a	Accelerator Pedal Position Sensor (Accelerator Pedal Sensor Assembly)

CAUTION / NOTICE / HINT

Tech Tips

Read Freeze Frame Data using the GTS. 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

READ VALUE USING GTS (ACCEL SENSOR OUT)

*a	Fully Depressed
*b	Fully Released

Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.

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

Read the value displayed on the GTS.

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	Higher than 0.02 V
Fully Depressed	2.6 to 4.5 V	3.4 to 4.75 V	Higher than 0.02 V

Result

Proceed to
OK
NG

OK

CHECK FOR INTERMITTENT PROBLEMS Click here

NG

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

*a	Front view of wire harness connector (to Accelerator Pedal Sensor Assembly)

Tech Tips

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

Disconnect the accelerator pedal sensor assembly connector.
Turn the ignition switch to ON.

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

Standard Voltage

Tester Connection	Condition	Specified Condition
A20-4 (VCPA) - A20-5 (EPA)	Ignition switch ON	4.5 to 5.5 V
A20-1 (VCP2) - A20-2 (EPA2)	Ignition switch ON	4.5 to 5.5 V

Result

Proceed to
OK
NG

NG

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

OK

CHECK HARNESS AND CONNECTOR (RESISTANCE OF ECM)

*a	Front view of wire harness connector (to Accelerator Pedal Sensor Assembly)

Disconnect the accelerator pedal sensor assembly connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A20-6 (VPA) - A20-5 (EPA)	Ignition switch off	37.05 to 40.95 kΩ
A20-3 (VPA2) - A20-2 (EPA2)	Ignition switch off	37.05 to 40.95 kΩ

Result

Proceed to
OK
NG

OK

REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

NG

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

Disconnect the accelerator pedal sensor assembly connector.
Disconnect the ECM connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A20-6 (VPA) - A22-47 (VPA)	Always	Below 1 Ω
A20-5 (EPA) - A22-48 (EPA)	Always	Below 1 Ω
A20-3 (VPA2) - A22-50 (VPA2)	Always	Below 1 Ω
A20-2 (EPA2) - A22-51 (EPA2)	Always	Below 1 Ω
A20-6 (VPA) or A22-47 (VPA) - Body ground and other terminals	Always	10 kΩ or higher
A20-5 (EPA) or A22-48 (EPA) - Body ground and other terminals	Always	10 kΩ or higher
A20-3 (VPA2) or A20-50 (VPA2) - Body ground and other terminals	Always	10 kΩ or higher
A20-2 (EPA2) or A22-51 (EPA2) - Body ground and other terminals	Always	10 kΩ or higher

Result

Proceed to
OK
NG

OK

REPLACE ECM Click here

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

Disconnect the accelerator pedal sensor assembly connector.
Disconnect the ECM connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A20-4 (VCPA) - A22-49 (VCPA)	Always	Below 1 Ω
A20-5 (EPA) - A22-48 (EPA)	Always	Below 1 Ω
A20-1 (VCP2) - A22-52 (VCP2)	Always	Below 1 Ω
A20-2 (EPA2) - A22-51 (EPA2)	Always	Below 1 Ω
A20-4 (VCPA) or A22-49 (VCPA) - Body ground and other terminals	Always	10 kΩ or higher
A20-5 (EPA) or A22-48 (EPA) - Body ground and other terminals	Always	10 kΩ or higher
A20-1 (VCP2) or A22-52 (VCP2) - Body ground and other terminals	Always	10 kΩ or higher
A20-2 (EPA2) or A22-51 (EPA2) - Body ground and other terminals	Always	10 kΩ or higher

Result

Proceed to
OK
NG

OK

REPLACE ECM Click here

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

SFI SYSTEM, Diagnostic DTC:P2120, P2121, P2122, P2123, P2125, P2127, P2128, P2138