Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit

Engine. Camry. Acv40 Gsv40
2Az-Fe Engine Control System. Camry. Acv40 Gsv40

DESCRIPTION

FAIL-SAFE

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (ACCELERATOR POSITION SENSOR)

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

INSPECT ECM (VCPA AND VCP2 VOLTAGE)

REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY (ACCELERATOR PEDAL POSITION SENSOR)

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

DTC P2120 Throttle / Pedal Position Sensor / Switch "D" Circuit

DTC P2122 Throttle / Pedal Position Sensor / Switch "D" Circuit Low Input

DTC P2123 Throttle / Pedal Position Sensor / Switch "D" Circuit High Input

DTC P2125 Throttle / Pedal Position Sensor / Switch "E" Circuit

DTC P2127 Throttle / Pedal Position Sensor / Switch "E" Circuit Low Input

DTC P2128 Throttle / Pedal Position Sensor / Switch "E" Circuit High Input

DTC P2138 Throttle / Pedal Position Sensor / Switch "D" / "E" Voltage Correlation


DESCRIPTION

HINT:
  1. This electronic throttle control system does not use a throttle cable.
  2. These DTCs relate to the accelerator pedal position sensor.
The accelerator pedal position 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 conditions. The voltage from this sensor, which is applied to terminals VPA and VPA2 of the ECM, varies between 0.5 V and 4.5 V in proportion to the operating angle of the accelerator pedal (throttle valve). A signal from VPA indicates the actual accelerator pedal operating 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.

Camry. Acv40 Gsv40.2Az-Fe Engine Control System.Sfi System. Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit


DTC No.
DTC Detection Condition
Trouble Area
P2120
VPA fluctuates rapidly beyond upper and lower malfunction thresholds for 0.5 seconds or more
(1 trip detection logic)
  1. Accelerator pedal position sensor
  2. ECM
P2122
VPA is 0.4 V or less for 0.5 seconds or more when accelerator pedal depressed
(1 trip detection logic)
  1. Accelerator pedal position sensor
  2. Open in VCP1 circuit
  3. Open or ground short in VPA circuit
  4. ECM
P2123
VPA is 4.8 V or more for 2.0 seconds or more
(1 trip detection logic)
  1. Accelerator pedal position sensor
  2. Open in EPA circuit
  3. ECM
P2125
VPA2 fluctuates rapidly beyond upper and lower malfunction thresholds for 0.5 seconds or more
(1 trip detection logic)
  1. Accelerator pedal position sensor
  2. ECM
P2127
VPA2 is 1.2 V or less for 0.5 seconds or more when accelerator pedal is fully released
(1 trip detection logic)
  1. Accelerator pedal position sensor
  2. Open in VCP2 circuit
  3. Open or ground short in VPA2 circuit
  4. ECM
P2128
Conditions (a) and (b) continue for 2.0 seconds or more (1 trip detection logic):
(a) VPA2 is 4.8 V or more
(b) VPA is between 0.4 V and 3.45 V
  1. Accelerator pedal position sensor
  2. Open in EPA2 circuit
  3. ECM
P2138
Condition (a) or (b) continues for 2.0 seconds or more (1 trip detection logic):
(a) 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
  1. Short between VPA and VPA2 circuits
  2. Accelerator pedal position sensor
  3. ECM

HINT:
When any of these DTCs are set, check the accelerator pedal position sensor voltage by entering the following menus using the intelligent tester: Powertrain / Engine and ECT / Data List / All Data / 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
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
2.5 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
HINT:
Accelerator pedal positions are expressed as voltages.

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 then turned off.

WIRING DIAGRAM


Camry. Acv40 Gsv40.2Az-Fe Engine Control System.Sfi System. Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit


INSPECTION PROCEDURE

HINT:
  1. These DTCs relate to the accelerator pedal position sensor.
  2. Read freeze frame data using the 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.
1.READ VALUE USING INTELLIGENT TESTER (ACCELERATOR POSITION SENSOR)
Camry. Acv40 Gsv40.2Az-Fe Engine Control System.Sfi System. Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

  1. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.

  1. Read the values displayed on the tester.

    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
    Released
    		0.5 to 1.1 V
    		1.2 to 2.0 V
    		More than 0.02V
    Fully Depressed
    		2.6 to 4.5 V
    		3.4 to 5.0 V
    Text in Illustration
    *a
    		Depressed
    *b
    		Released


OK
Go to step 5

NG
Go to step 2

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

  1. Disconnect the accelerator pedal sensor assembly connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance (Check for Open):

    Tester Connection
    		Condition
    		Specified Condition
    A17-6 (VPA) - A24-55 (VPA)
    		Always
    		Below 1 Ω
    A17-5 (EPA) - A24-59 (EPA)
    		Always
    		Below 1 Ω
    A17-4 (VCPA) - A24-57 (VCPA)
    		Always
    		Below 1 Ω
    A17-3 (VPA2) - A24-56 (VPA2)
    		Always
    		Below 1 Ω
    A17-2 (EPA2) - A24-60 (EPA2)
    		Always
    		Below 1 Ω
    A17-1 (VCP2) - A24-58 (VCP2)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):

    Tester Connection
    		Condition
    		Specified Condition
    A17-6 (VPA) or A24-55 (VPA) - Body ground
    		Always
    		10 kΩ or higher
    A17-5 (EPA) or A24-59 (EPA) - Body ground
    		Always
    		10 kΩ or higher
    A17-4 (VCPA) or A24-57 (VCPA) - Body ground
    		Always
    		10 kΩ or higher
    A17-3 (VPA2) or A24-56 (VPA2) - Body ground
    		Always
    		10 kΩ or higher
    A17-2 (EPA2) or A24-60 (EPA2) - Body ground
    		Always
    		10 kΩ or higher
    A17-1 (VCP2) or A24-58 (VCP2) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the accelerator pedal sensor assembly connector.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR - ECM)
OK


3.INSPECT ECM (VCPA AND VCP2 VOLTAGE)


    Camry. Acv40 Gsv40.2Az-Fe Engine Control System.Sfi System. Dtc P2120 Throttle / Pedal Position Sensor / Switch D Circuit

  1. Disconnect the accelerator pedal sensor assembly connector.

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A17-4 (VCPA) - A17-5 (EPA)
    		Ignition switch ON
    		4.5 to 5.5 V
    A17-1 (VCP2) - A17-2 (EPA2)
    		Ignition switch ON
    		4.5 to 5.5 V
    Text in Illustration
    *1
    		Front view of wire harness connector
    (to Accelerator Pedal Sensor Assembly)

  1. Reconnect the accelerator pedal sensor assembly connector.



NG
REPLACE ECM (CAMRY_ACV40 RM0000017UO02YX.html)
OK


4.REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY (ACCELERATOR PEDAL POSITION SENSOR)

  1. Replace the accelerator pedal sensor assembly (CAMRY_ACV40 RM0000017UL009X.html).


NEXT


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

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

  1. Clear the DTCs (CAMRY_ACV40 RM000000PDK0LEX.html).

  1. Fully depress and release the accelerator pedal.

  1. Check that 5 seconds or more have elapsed since the ignition switch was turned to ON.

  1. Enter the following menus: Powertrain / Engine and ECT / DTC.

  1. Read the DTCs.

    Result:

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


B
END
A

REPLACE ECM (CAMRY_ACV40 RM0000017UO02YX.html)