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Home >> Lexus >> 2004 >> IS 300 Base, Standard >> Repair and Diagnosis (Single Page) >> Engine Performance >> Engine Control System - Diagnosis >> Circuit Inspection >> DTC P2120: Throttle/pedal Position Sensor/Switch "D" Circuit, DTC P2122: Throttle/pedal Position Sensor/Switch "D" Circuit, DTC P2123: Throttle/Pedal Position Sensor/Switch "D" Circuit High Input >> Inspection Procedure >> Hand-held tester
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Hand-held tester

  1. Connect hand-held tester, and read voltage for accelerator pedal position sensor data. 

    PREPARATION: 

    1. Connect the hand-held tester to DLC3.
    2. Turn the ignition switch ON and push the hand-held tester main switch ON.

    CHECK: 

    Read the voltage for the accelerator pedal position sensor data.

    Fig 1: Identifying Accelerator Pedal Position
    G01496483Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    Fig 2: Accelerator Pedal Chart
    G01496482Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. OK: Go to step   6 . 
    2. NG: Go to next step. 
  2. Check accelerator pedal position sensor (See  THROTTLE BODY  ). 
    1. NG: Replace accelerator pedal position sensor. 
    2. NG: Go to next step. 
  3. Check voltage between terminals VC and E2 of ECM connector 

    PREPARATION: 

    1. Remove the ECM hood (See ENGINE CONTROL MODULE (ECM) ).
    2. Turn the ignition switch ON.

    CHECK: 

    Measure the voltage between terminals VC and E2 of the ECM connector.

    Fig 3: Measuring Voltage Between Terminals VC & E2 Of ECM Connector
    G01496484Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    Voltage: 5.4 to 5.5 V 

    1. NG: Replace ECM (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
    2. OK: Go to next step. 
  4. Check voltage between terminals VPA and E2, and VPA2 and E2 of ECM connector 

    PREPARATION: 

    1. Remove the ECM hood (See ENGINE CONTROL MODULE (ECM) ).
    2. Turn the ignition switch ON.

    CHECK: 

    Measure the voltage between terminals VPA and E2, and VPA2 and E2 of the e ECM connector.

    Fig 4: Measuring Voltage Between Terminals VPA & E2 And VPA2 & E2 Of ECM Connector
    G01496486Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    Fig 5: Accelerator Pedal & Voltage Chart
    G01496485Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. OK: Replace ECM (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
    2. NG: Go to next step. 
  5. Check for open and short in harness and connector between accelerator pedal position sensor and ECM (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
    1. NG: Repair or replace harness or connector 
    2. OK: Go to next step. 
  6. Is the DTC P2120, P2122, or P2123 being output again? 

    PREPARATION: 

    1. Clear the DTC (See PRE-CHECK  ).
    2. Start the engine.
    3. Run the engine at idle for 15 seconds or more.

    CHECK: 

    1. Read the DTC (See PRE-CHECK  ).

    Result: 

    Fig 6: Display (DTC Output) Chart
    G01496487Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. B: System OK 
    2. A: Replace ECM (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ).