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DTC C1340: Stoplight switch: Diagnosis

Required Special Tools: 

  1. STEP 1. Using scan tool MB991958, diagnose the CAN bus line. 
    CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
    1. Connect scan tool MB991958 to the data link connector.
    2. Turn the ignition switch to the "ON" position.
    3. Diagnose the CAN bus line.
    4. Turn the ignition switch to the "LOCK" (OFF) position.

      Q: Is the CAN bus line found to be normal? 

      1. YES:  Go to Step  3.
      2. NO:  Repair the CAN bus line (Refer to DIAGNOSIS . Then go to Step 2.
        Fig 1: Connecting Special Tool MB991910 To Data Link Connector
        G04230562Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  2. STEP 2. Recheck for diagnostic trouble code. 
    CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
    1. Turn the ignition switch to the "ON" position.
    2. Erase the DTC.
    3. Turn the ignition switch to the "LOCK" (OFF) position.
    4. Turn the ignition switch to the "ON" position.
    5. Check if the DTC is set.
    6. Turn the ignition switch to the "LOCK" (OFF) position.

      Q: Is DTC C1340 set? 

      1. YES:  Go to Step 3.
      2. NO:  The procedure is complete.
        Fig 2: Connecting Special Tool MB991910 To Data Link Connector
        G04230562Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  3. STEP 3. Check the stoplight operation. 
    1. Turn the ignition switch to the "ON" position.
    2. Check the operation of the stoplight when the brake pedal is operated.

      OK: 

      Brake pedal depressed: ON 

      Brake pedal released: OFF 

      Q: Is the check result normal? 

      1. YES:  Go to Step 4.
      2. NO:  Go to Step  6.
  4. STEP 4. Connector check: A-38 TCL/ASC-ECU connector, C-28 joint connector (1). 

    Q: Is the check result normal? 

    1. YES:  Go to Step 5.
    2. NO:  Repair or replace the damaged component(s). Then go to Step  16.
  5. STEP 5. Measure the resistance at the C-28 joint connector (1). 
    1. Disconnect the connector C-28 joint connector (1) and A-38 TCL/ASC-ECU connector, and measure the wiring harness-side connector.
    2. Measure the resistance between the C-28 joint connector (1) terminal 15 and A-38 TCL/ASC-ECU connector terminal 41.

      OK: Continuity exists (2 ohms or less) 

      Q: Is the check result normal? 

      1. YES:  Go to Step  15.
      2. NO:  Repair the harness wire. Then go to Step  16.
  6. STEP 6. Connector check: A-38 TCL/ASC-ECU connector, C-28 joint connector (1), C-103 stoplight switch connector, C-26 intermediate connector, F-02 intermediate connector (ECLIPSE), F-05 (standard type rear spoiler) or F-30 (large type rear spoiler) high-mounted stoplight, F-07 rear combination light (RH), F-14 rear combination light (LH) 

    Q: Is the check result normal? 

    1. YES:  Go to Step 7.
    2. NO:  Repair or replace the damaged component(s). Then go to Step  16.
  7. STEP 7. Check for stoplight switch installation 

    Refer to ON-VEHICLE SERVICE .

    Q: Is the check result normal? 

    1. YES:  Go to Step 8.
    2. NO:  Install the stoplight switch correctly (Refer to ON-VEHICLE SERVICE . Then go to Step  16.
  8. STEP 8. Check for stoplight switch 

    Refer to BRAKE PEDAL INSPECTION .

    Q: Is the check result normal? 

    1. YES:  Go to Step 9.
    2. NO:  Replace the stoplight switch (Refer to BRAKE PEDAL . Then go to Step  16.
  9. STEP 9. Check the fuse No. 11. 

    Visually check for melted fuse.

    Q: Is the check result normal? 

    1. YES:  Go to Step  13.
    2. NO:  Go to Step 10.
  10. STEP 10. Measure the resistance at the C-103 stoplight switch connector. 
    1. Disconnect the connector C-103, and measure at the wiring harness-side connector.
    2. Remove fuse No. 11.
    3. Measure the resistance between the C-103 stoplight switch connector terminal 2 and body ground.

      OK: No continuity 

      Q: Is the check result normal? 

      1. YES:  Go to Step 11.
      2. NO:  The wiring harness between fuse No. 11 and C-103 stoplight switch connector terminal 2 is shorted to ground. Repair the wiring harness. Then, replace fuse No. 11. Then go to Step  16.
  11. STEP 11. Measure the resistance at the C-103 stoplight switch connector. 
    1. Disconnect the connector C-103, and measure at the wiring harness-side connector.
    2. Disconnect the connector C-28 joint connector (1).
    3. Measure the resistance between the C-103 stoplight switch connector terminal 1 and body ground.

      OK: No continuity 

      Q: Is the check result normal? 

      1. YES:  Go to Step 12.
      2. NO:  The wiring harness between C-28 joint connector (1) terminal 12 and C-103 stoplight switch connector terminal 1 is shorted to ground. Repair the wiring harness. Then, replace fuse No. 11. Then go to Step  16.
  12. STEP 12. Measure the resistance at the C-28 joint connector (1). 
    1. Disconnect the connector C-28, and measure at the wiring harness-side connector.
    2. Disconnect the connector A-38 TCL/ASC-ECU connector.
    3. Measure the resistance between the C-28 joint connector (1) terminal 15 and body ground.

      OK: No continuity 

      Q: Is the check result normal? 

      1. YES:  The wiring harness between C-28 joint connector (1) terminal 17 and F-05 (standard type rear spoiler) or F-30 (large type rear spoiler) high-mounted stoplight connector terminal 2 or the wiring harness F-07 rear combination light (RH) connector terminal 2 and F-11 rear combination light (LH) connector terminal 2 is shorted to ground. Repair the wiring harness. Then, replace fuse No. 11. Then go to Step  15.
      2. NO:  The wiring harness between C-28 joint connector (1) terminal 15 and A-38 TCL/ASC-ECU connector terminal 41 is shorted to ground. Repair the wiring harness. Then, replace fuse No. 11. Then go to Step  16.
  13. STEP 13. Measure the resistance at the C-103 stoplight switch connector. 
    1. Disconnect the connector C-103, and measure at the wiring harness-side connector.
    2. Remove fuse No. 11.
    3. Measure the resistance between the C-103 stoplight switch connector terminal 2 and Fuse No. 11.

      OK: Continuity exists (2 ohms or less) 

      Q: Is the check result normal? 

      1. YES:  Go to Step 14.
      2. NO:  An open circuit is present in the wiring harness between fuse No. 11 and C-103 stoplight switch connector terminal 2. Repair the wiring harness. Then go to Step  16.
  14. STEP 14. Measure the resistance at the C-103 stoplight switch connector. 
    1. Disconnect the connector C-103, and measure at the wiring harness-side connector.
    2. Disconnect the connector C-28 joint connector (1).
    3. Measure the resistance between the C-103 stoplight switch connector terminal 1 and C-28 joint connector (1) terminal 12.

      OK: Continuity exists (2 ohms or less) 

      Q: Is the check result normal? 

      1. YES:  Go to Step 15.
      2. NO:  An open circuit is present in the wiring harness between C-28 joint connector (1) terminal 12 and C-103 stoplight switch connector terminal 1. Repair the wiring harness. Then go to Step  16.
  15. STEP 15. Recheck for diagnostic trouble code. 

    Check again if the DTC is set.

    1. Turn the ignition switch to the "ON" position.
    2. Erase the DTC.
    3. Turn the ignition switch to the "LOCK" (OFF) position.
    4. Turn the ignition switch to the "ON" position.
    5. Check if the DTC is set.
    6. Turn the ignition switch to the "LOCK" (OFF) position.

      Q: Is DTC C1340 set? 

      1. YES:  Replace the hydraulic unit (integrated with TCL/ASC-ECU). Then go to Step 16.
      2. NO:  It can be assumed that this malfunction is intermittent. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION .
        Fig 3: Connecting Special Tool MB991910 To Data Link Connector
        G04230562Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  16. STEP 16. Recheck for diagnostic trouble code. 

    Check again if the DTC is set.

    1. Turn the ignition switch to the "ON" position.
    2. Erase the DTC.
    3. Turn the ignition switch to the "LOCK" (OFF) position.
    4. Turn the ignition switch to the "ON" position.
    5. Drive the vehicle at 12 mph (20 km/h) or more for 6 minutes or more (there is no need to drive continuously).
    6. Stop the vehicle with braking at 25 mph (40 km/h) or more.
    7. Check if the DTC is set.
    8. Turn the ignition switch to the "LOCK" (OFF) position.

      Q: Is DTC C1340 set? 

      1. YES:  Go to Step  1.
      2. NO:  The procedure is complete.
        Fig 4: Connecting Special Tool MB991910 To Data Link Connector
        G04230562Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
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