Toyota Venza: Throttle / Pedal Position Sensor / Switch "D" Circuit (P2120,P2122,P2123,P2125,P2127,P2128,P2138)

Toyota Venza Service Manual / 1ar-fe Engine Control / Sfi System / Throttle / Pedal Position Sensor / Switch "D" Circuit (P2120,P2122,P2123,P2125,P2127,P2128,P2138)

DESCRIPTION

HINT:

This Electronic Throttle Control System (ETCS) does not use a throttle cable.
These DTCs relate to the accelerator pedal sensor assembly.

The accelerator pedal sensor assembly is mounted on the accelerator pedal bracket 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 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 sensor assembly itself.

The ECM monitors the actual accelerator pedal 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 Condition	Trouble Area
P2120	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
P2122	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
P2123	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
P2125	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
P2127	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
P2128	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
P2138	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

HINT:

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

Trouble Area	Accel Sensor Out No. 1 When Accelerator Pedal Released	Accel Sensor Out No. 2 When Accelerator Pedal Released	Accel Sensor Out No. 1 When Accelerator Pedal Fully Depressed	Accel Sensor Out No. 2 When Accelerator Pedal Fully Depressed
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 less 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 drops below 0.4 V for more than 0.5 seconds when the accelerator pedal is fully depressed, DTC P2122 is stored.

MONITOR STRATEGY

Related DTCs	P2120: Accelerator Pedal Position Sensor 1 Range Check (Chattering) 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 Correlation
Required Sensors/Components (Main)	Accelerator pedal position sensor assembly
Required Sensors/Components (Related)	-
Frequency of Operation	Continuous
Duration	0.5 seconds: P2120, P2122, P2125 and P2127 2.0 seconds: P2123, P2128 and P2138
MIL Operation	Immediate
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever following DTCs not stored	None
Either of the following conditions is met:	-
1. Time after ignition switch off to ON	0.012 seconds or more
2. Command to electronic throttle actuator power	ON

TYPICAL MALFUNCTION THRESHOLDS

P2120

Either of the following conditions is met:	1 or 2
1. Both of the following conditions are met	(a) and (b)
(a) VPA voltage	0.4 V or less
(b) VPA2 voltage - Learned VPA2 accelerator off position voltage	0.04 V or higher
2. VPA voltage	4.8 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	(a) and (b)
(a) VPA2 voltage	1.2 V or less
(b) 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:	1 or 2
1. Difference between VPA and VPA 2 voltages	0.02 V or less
2. 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, and less than 4.8 V
VPA2 voltage	Higher than 1.2, and less than 4.8 V
Difference between VPA and VPA2 voltages	Higher than 0.02 V

CONFIRMATION DRIVING PATTERN

Connect the Techstream to the DLC3.
Turn the ignition switch to ON and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) (See page ).

Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the Techstream on [A].
Fully depress and release the accelerator pedal [B].
Check that 5 seconds or more have elapsed since the DTCs were cleared.
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.
Input the DTC: P2120, P2122, P2123, P2125, P2127, P2128 or P2138.

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] and [C] again.

If no pending DTC is output, perform a universal trip and check for permanent DTCs (See page ).
HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

FAIL-SAFE

When any of DTCs P2120, P2121, P2122, P2123, P2125, P2127, P2128 and P2138 is stored, the ECM enters fail-safe mode. If either circuit 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:

These DTCs relate to the accelerator pedal position sensor.
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 (ACCELERATOR PEDAL SENSOR ASSEMBLY)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Powertrain / Engine / Data List / Accel Sensor Out No. 1 and 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	More than 0.02 V

Text in Illustration

*a	Fully Depressed
*b	Fully Released

CHECK FOR INTERMITTENT PROBLEMS

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

(a) Disconnect the accelerator pedal sensor assembly connector.

(b) Disconnect the ECM connector.

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
A32-6 (VPA) - A49-55 (VPA)	Always	Below 1 Ω
A32-5 (EPA) - A49-59 (EPA)	Always	Below 1 Ω
A32-4 (VCPA) - A49-57 (VCPA)	Always	Below 1 Ω
A32-3 (VPA2) - A49-56 (VPA2)	Always	Below 1 Ω
A32-2 (EPA2) - A49-60 (EPA2)	Always	Below 1 Ω
A32-1 (VCP2) - A49-58 (VCP2)	Always	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
A32-6 (VPA) or A49-55 (VPA) - Body ground	Always	10 kΩ or higher
A32-5 (EPA) or A49-59 (EPA) - Body ground	Always	10 kΩ or higher
A32-4 (VCPA) or A49-57 (VCPA) - Body ground	Always	10 kΩ or higher
A32-3 (VPA2) or A49-56 (VPA2) - Body ground	Always	10 kΩ or higher
A32-2 (EPA2) or A49-60 (EPA2) - Body ground	Always	10 kΩ or higher
A32-1 (VCP2) or A49-58 (VCP2) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	CHECK ECM (VCPA AND VCP2 VOLTAGE)

(a) Disconnect the accelerator pedal sensor assembly connector.

(b) Turn the ignition switch to ON.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A32-4 (VCPA) - A32-5 (EPA)	Ignition switch ON	4.5 to 5.5 V
A32-1 (VCP2) - A32-2 (EPA2)	Ignition switch ON	4.5 to 5.5 V

Text in Illustration

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

REPLACE ECM

4.	REPLACE ACCELERATOR PEDAL ASSEMBLY

(a) Replace the accelerator pedal assembly (See page ).

5.	CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL SENSOR ASSEMBLY DTCS)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Clear the DTCs (See page ).

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

(g) Enter the following menus: Powertrain / Engine / Trouble Codes.

(h) Read the DTCs.

Result	Proceed to
DTC P2120, P2122, P2123, P2125, P2127, P2128, and/or P2138 are output	A
DTC is not output	B

REPLACE ECM

END

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