DTC P2121 Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance 1GR-FE

DESCRIPTION

MONITOR DESCRIPTION

FAIL-SAFE

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (ACCELERATOR POSITION SENSOR)

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

REPLACE ACCELERATOR PEDAL ROD ASSEMBLY

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

DTC P2121 Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance

Description DTC P2121

Refer to DTC P2120 .

DTC Code DTC Detection Condition Trouble Area
P2121 Either of following conditions 1 or 2 met for 0.5 seconds (1 trip detection logic)
  1. Difference between VPA and VPA2 is less than 0.4 V, or more than 1.2 V. (learned value of accelerator off position)
  2. Difference between VPA and VPA2 is greater than or equal to the specified value.
  1. Accelerator Pedal Position (APP) sensor
  2. ECM

Monitor description

When the difference between the output voltages of VPA and VPA2 deviates from the standard, the ECM determines that the accelerator pedal position sensor is malfunctioning. The ECM turns on the MIL and stores the DTC.

Fail-safe

The accelerator pedal position sensor has two (main and sub) sensor circuits. If a malfunction occurs in either of the sensor circuits, the ECM detects the abnormal signal voltage difference between the two sensor circuits and switches to limp mode. In limp mode, the functioning circuit is used to calculate the accelerator pedal opening angle to allow the vehicle to continue to be driven. If both circuits malfunction, the ECM regards the opening angle of the accelerator pedal as being fully closed. In this case, the throttle valve remains closed as if the engine is idling.

If a pass condition is detected and then the ignition switch is turned off, the fail-safe operation stops and the system returns to a normal condition.

Wiring diagram

Refer to DTC P2120.

Inspection procedure

HINT:

  1. Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. 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.
  2. This DTC relates to the Accelerator Pedal Position (APP) sensor.

1.READ VALUE USING INTELLIGENT TESTER (ACCELERATOR POSITION SENSOR)

Connect the intelligent tester to the DLC3. DTC P2121 Land Cruiser 1GR-FE

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the tester on.

  1. Enter the following menus: Powertrain / Engine and ECT / Data List / ETCS / Accelerator Position No.1 and Accelerator Position No.2.

  1. Read the value displayed on the tester.

    Standard Voltage:

    Accelerator Pedal Operation Accelerator Position No. 1 Accelerator Position No. 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
    Result
    Result Proceed to
    OK A
    NG B
  A  
Go to step 3
 
B  
   

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

Disconnect the Accelerator Pedal Position (APP) sensor connector. DTC P2121 Land Cruiser 1GR-FE

  1. Disconnect the Accelerator Pedal Position (APP) sensor connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance (Check for Open):

    for LHD
    Tester Connection Condition Specified Condition
    A31-6 (VPA) - A38-55 (VPA) Always Below 1 ?
    A31-5 (EPA) - A38-59 (EPA) Always Below 1 ?
    A31-4 (VCPA) - A38-57 (VCPA) Always Below 1 ?
    A31-3 (VPA2) - A38-56 (VPA2) Always Below 1 ?
    A31-2 (EPA2) - A38-60 (EPA2) Always Below 1 ?
    A31-1 (VCP2) - A38-58 (VCP2) Always Below 1 ?
    for RHD
    Tester Connection Condition Specified Condition
    A31-6 (VPA) - A52-55 (VPA) Always Below 1 ?
    A31-5 (EPA) - A52-59 (EPA) Always Below 1 ?
    A31-4 (VCPA) - A52-57 (VCPA) Always Below 1 ?
    A31-3 (VPA2) - A52-56 (VPA2) Always Below 1 ?
    A31-2 (EPA2) - A52-60 (EPA2) Always Below 1 ?
    A31-1 (VCP2) - A52-58 (VCP2) Always Below 1 ?

    Standard Resistance (Check for Short):

    for LHD
    Tester Connection Condition Specified Condition
    A31-6 (VPA) or A38-55 (VPA) - Body ground Always 10 k? or higher
    A31-5 (EPA) or A38-59 (EPA) - Body ground Always 10 k? or higher
    A31-4 (VCPA) or A38-57 (VCPA) - Body ground Always 10 k? or higher
    A31-3 (VPA2) or A38-56 (VPA2) - Body ground Always 10 k? or higher
    A31-2 (EPA2) or A38-60 (EPA2) - Body ground Always 10 k? or higher
    A31-1 (VCP2) or A38-58 (VCP2) - Body ground Always 10 k? or higher
    for RHD
    Tester Connection Condition Specified Condition
    A31-6 (VPA) or A52-55 (VPA) - Body ground Always 10 k? or higher
    A31-5 (EPA) or A52-59 (EPA) - Body ground Always 10 k? or higher
    A31-4 (VCPA) or A52-57 (VCPA) - Body ground Always 10 k? or higher
    A31-3 (VPA2) or A52-56 (VPA2) - Body ground Always 10 k? or higher
    A31-2 (EPA2) or A52-60 (EPA2) - Body ground Always 10 k? or higher
    A31-1 (VCP2) or A52-58 (VCP2) - Body ground Always 10 k? or higher
  NG  
REPAIR OR REPLACE HARNESS OR CONNECTOR
 
OK  
   

3.REPLACE ACCELERATOR PEDAL ROD ASSEMBLY

  1. Replace the accelerator pedal rod assembly .

NEXT  
   

4.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 and turn the tester on.

  1. Clear the DTCs .

  1. Start the engine.

  1. Allow the engine to idle for 15 seconds.

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

  1. Read the DTCs.

    Result
    Result Proceed to
    P2121 A
    No output B
  B  
SYSTEM OK
 
A  
   
REPLACE ECM