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Home >> Mitsubishi >> 2003 >> Montero XLS >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Diagnostic Trouble Code Procedures >> Diagnostic Trouble Code Procedures < Transfer> >> DTC 21: Accelerator Pedal Position Sensor System >> Diagnosis
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DTC 21: Accelerator Pedal Position Sensor System: Diagnosis

Required Special Tool: 

  1. STEP 1. Using scan tool MB991502, check data list item 01: Accelerator Pedal Position Sensor. 
    CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
    1. Connect scan tool MB991502 to the data link connector.
      Fig 1: Connecting Scan Tool MB991502 To Data Link Connector
      G01850901Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Set scan tool MB991502 to data reading mode for item 01, Accelerator Pedal Position Sensor - Active trac 4WD II.
      • With the throttle valve in idle position, voltage should measure between 905 and 1,165 mV
      • With the throttle valve in full-open position, voltage should measure between 4,035 mV or more.
    4. Turn the ignition switch to the "LOCK" (OFF) position.

    Q: Is the measured voltage between 905 and 1,165 mV at idle, and between 4,035 mV or more in the full-open position? 

    1. YES :  It can be assumed that this malfunction is intermittent. Refer to HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS - How to Cope with Intermittent Malfunction.
    2. NO:  Go to Step 2.
  2. STEP 2. Using scan tool MB991502, read the MFI diagnostic trouble code. 
    1. Connect scan tool MB991502 to the data link connector.
      Fig 2: Connecting Scan Tool Mb991502 To Data Link Connector
      G01850902Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Check for MFI diagnostic trouble code.
    4. Turn the ignition switch to the "LOCK" (OFF) position.

    Q: Are MFI DTCS P2126, P2127, P2128 set? 

    1. YES :  Refer to DIAGNOSTIC TROUBLE CODE DEFINITIONS .
    2. NO :  Go to Step 3.
  3. STEP 3. Measure the accelerator pedal position sensor output voltage at transfer-ECU connector E-109 by backprobing. 
    1. Do not disconnect connector E-109.
      Fig 3: Identifying Transfer-ECU Connector E-109 Location And Terminal View
      G01850903Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Measure the voltage between terminal 5 and ground by backprobing.
      • With the throttle valve in idle position, voltage should measure between 0.905 and 1.165 volts.
      • With the throttle valve in full-open position, voltage should measure between 4.035 volts or more.
      Fig 4: Measuring Voltage Between Terminal 5 And Ground By Backprobing
      G01850904Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    4. Turn the ignition switch to the "LOCK" (OFF) position.

    Q: Is the measured voltage between 0.535 and 0.735 volt at idle, and between 4.5 and 5.5 volts in the full-open position? 

    1. YES :  Go to Step  6 .
    2. NO :  Go to Step 4.
  4. STEP 4. Check transfer-ECU connector E-109 and intermediate connector E-114 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 
    Fig 5: Identifying Transfer-ECU Connector E-109 And Intermediate Connector E-114 Location And Terminals View
    G01850905Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are the connectors and terminals in good condition? 

    1. YES :  Go to Step 5.
    2. NO :  Repair or replace the damaged components. Refer to HARNESS CONNECTOR INSPECTION .
  5. STEP 5. Check harness for open circuit for damage between accelerator pedal position sensor connector D-138 terminal 6 and transfer-ECU connector E-109 terminal 5. 
    Fig 6: Identifying Accelerator Pedal Position Sensor Connector D-138 Location And Terminal View
    G01850906Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 7: Identifying Transfer-ECU Connector E-109 Location And Terminal View
    G01850907Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Is the harness wire in good condition? 

    1. YES :  Go to Step  7 .
    2. NO :  Repair or replace the harness wire.
  6. STEP 6. Check transfer-ECU connector E-109 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 
    Fig 8: Identifying Transfer-ECU Connector E-109 Location And Terminal View
    G01850908Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are the connector and terminals in good condition? 

    1. YES :  Go to Step 7.
    2. NO :  Repair or replace the damaged components. Refer to HARNESS CONNECTOR INSPECTION .
  7. STEP 7. Using scan tool MB991502, check data list item 01: Accelerator Pedal Position Sensor. 
    CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
    1. Connect scan tool MB991502 to the data link connector.
      Fig 9: Connecting Scan Tool MB991502 To Data Link Connector
      G01850909Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Set scan tool MB991502 to the data reading mode for item 01, Accelerator Pedal Position Sensor - Active trac 4WD II.
      • With the throttle valve in idle position, voltage should measure between 905 and 1,165 mV.
      • With the throttle valve in full-open position, voltage should measure between 4,035 mV or more.
    4. Turn the ignition switch to the "LOCK" (OFF) position.

    Q: Is the measured voltage between 905 and 1,165 mV at idle, and between 4,035 mV or more in the full-open position? 

    1. YES :  It can be assumed that this malfunction is intermittent. Refer to HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS - How to Cope with Intermittent Malfunction.
    2. NO :  Replace the transfer-ECU.
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