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DTC 22: Stoplight Switch System: Diagnosis

WARNING: This page is about a different variant/trim than selected.

Required Special Tools: 

  1. STEP 1. Using scan tool MB991958, check data list item 05: Stoplight Switch. 
    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.
      Fig 1: Connecting Scan Tool MB991958 To Data Link Connector
      G00809749Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Set scan tool MB991958 to data reading mode.
      • Item 05, Stoplight Switch.
        • When the brake pedal is depressed, the display on scan tool MB991958 should be "ON".
        • When the brake pedal is released, the display on scan tool MB991958 should be "OFF".
    4. Turn the ignition switch to the "LOCK" (OFF) position.
    5. Disconnect scan tool MB991958.

    Q: Is the switch operating properly? 

    1. YES:  Go to  Step 14.
    2. NO:  Go to Step 2.
  2. STEP 2. Check the stoplight operation. 

    Check the stoplight operation.

    • When the brake pedal is depressed, the stoplight will illuminate.
    • When the brake pedal is released, the stoplight does not illuminate.

    Q: Is the stoplight will illuminate (when the brake pedal is depressed) and the stoplight does not illuminate (when the brake pedal is released)? 

    1. YES:  Go to Step 3.
    2. NO:  Go to  Step 6.
  3. STEP 3. Measure the terminal voltage at ECM connector C-135 < M/T > or PCM connector C-136 < A/T >. 
    1. Do not disconnect ECM connector C-135 < M/T > or PCM connector C-136 < A/T >.
      Fig 2: Identifying Connectors C-135 (M/T), C-136 (A/T)
      G00809750Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Measure the voltage between ECM connector C-135 < M/T > terminal 39 or PCM connector C-136 < A/T > terminal 39 and ground by backprobing.
      • When the brake pedal is depressed, the voltage should measure battery positive voltage (approximately 12 volts).
      • When the brake pedal is released, the voltage should measure 1 volt or less.
        Fig 3: Measuring Voltage Between Connector C-135 (M/T) or C-136 (A/T) and Ground
        G00809751Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    4. Turn the ignition switch to the "LOCK" (OFF) position.

    Q: Is the measured voltage battery positive voltage (approximately 12 volts) when the brake pedal is depressed and 1 volt or less when the brake pedal is released? 

    1. YES:  Go to  Step 13.
    2. NO:  Go to Step 4.
  4. STEP 4. Check ECM connector C-135 < M/T > or PCM connector C-136 < A/T > and joint connector (6) C-105 and intermediate connector C-124 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 
    Fig 4: Identifying Connector C-135 (M/T), C-136 (A/T)
    G00809752Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 5: Identifying Connector C-105, C-124
    G00809753Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are there connectors and terminals in good condition? 

    1. YES:  Go to Step 5.
    2. NO:  Repair or replace the damaged components. Then go to  Step 23.
  5. STEP 5. Check the harness wire between ECM connector C-135 < M/T > terminal 9 or PCM connector C-136 < A/T > terminal 9 and stoplight switch connector C-102 terminal 1 for damage. 
    Fig 6: Identifying Connector C-135 (M/T), C-136 (A/T)
    G00809754Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 7: Identifing Connector C-102
    G00809755Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are there harness wires in good condition? 

    1. YES:  Go to  Step 13.
    2. NO:  Repair the damaged harness wire. Then go to  Step 23.
  6. STEP 6. Measure the power supply voltage at stoplight switch connector C-102. 
    1. Disconnect stoplight switch connector C-102.
      Fig 8: Disconnecting Connector C-102
      G00809756Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Measure the voltage between stoplight switch connector C-102 terminal 2 and ground.
      • Voltage should be battery positive voltage.
        Fig 9: Measuring Voltage
        G00809757Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Connect stoplight switch connector C-102.

    Q: Is the measured voltage battery positive voltage (approximately 12 volts)? 

    1. YES:  Go to  Step 10.
    2. NO:  Go to Step 7.
  7. STEP 7. Check stoplight switch connector C-102 and intermediate connector C-129 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 
    Fig 10: Identifying Connector C-102, C-129
    G00809758Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are there connectors and terminals in good condition? 

    1. YES:  Go to Step 8.
    2. NO:  Repair or replace the damaged components. Then go to  Step 23.
  8. STEP 8. Check the harness wire between stoplight switch connector C-102 terminal 2 and fuse number 10 at the relay box in engine compartment for damage. 
    Fig 11: Identifying Connector C-102
    G00809759Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 12: Identifying Fuse No. 10
    G00809760Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are there harness wires in good condition? 

    1. YES:  Go to Step 9.
    2. NO:  Repair the damaged harness wire. Then go to  Step 23.
  9. STEP 9. Check the fuse number 10 at the relay box in engine compartment. 
    Fig 13: Checking Fuse No. 10
    G00809761Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Is the fuse in good condition? 

    1. YES:  Go to Step 10.
    2. NO:  Check the stoplight system harness and replace the fuse. Then go to  Step 23.
  10. STEP 10. Check the stoplight switch. 
    1. Remove the stoplight switch.
    2. Connect an ohmmeter to the stoplight switch between terminals 1 and 2.
      Fig 14: Connecting Ohmmeter To Stoplight Switch
      G00809762Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Check for continuity between the terminals when the plunger of the stoplight switch is pushed in and when it is released.
      Fig 15: Checking Continuity
      G00809763Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    4. The stoplight switch is operating properly if the circuit is open between terminals 1 and 2 when the plunger is pushed in to a depth of within 4.0 mm (0.16 inch) from the outer case edge surface, and if the resistance value is less than 2 ohms between terminals 1 and 2 when it is released.

    Q: Is the stoplight switch between terminals 1 and 2 still open circuit even with the plunger pushed in, and resistance value is less than 2 ohms when plunger is released? 

    1. YES:  Install the stoplight switch. Then go to Step 11.
    2. NO:  Replace the stoplight switch. Then go to  Step 23.
  11. STEP 11. Check stoplight switch connector C-102 and intermediate connector C-124 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 
    Fig 16: Identifying Connectors: C-102, C-124
    G00809764Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are there connectors and terminals in good condition? 

    1. YES:  Go to Step 12.
    2. NO:  Repair or replace the damaged components. Then go to  Step 23.
  12. STEP 12. Check the harness wire between stoplight switch connector C-102 terminal 1 and intermediate connector C-124 terminal 14 for damage. 
    Fig 17: Identifying Connectors C-102, C-124
    G00809765Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Is the harness wire in good condition? 

    1. YES:  Go to Step 13.
    2. NO:  Repair the damaged harness wire. Then go to  Step 23.
  13. STEP 13. Using scan tool MB991958, check data list item 05: Stoplight Switch. 
    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.
      Fig 18: Connecting Scan Tool MB991958 To Data Link Connector
      G00809766Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Set scan tool MB991958 to data reading mode.
      • Item 05, Stoplight Switch.
        • When the brake pedal is depressed, the display on scan tool MB991958 should be "ON".
        • When the brake pedal is released, the display on scan tool MB991958 should be "OFF".
    4. Turn the ignition switch to the "LOCK" (OFF) position.
    5. Disconnect scan tool MB991958.

    Q: Is the switch operating properly? 

    1. YES:  Go to  Step 22.
    2. NO:  Replace the ECM < M/T > or PCM < A/T > [Refer to ENGINE CONTROL MODULE (ECM) AND POWERTRAIN CO ]. Then go to  Step 23.
  14. STEP 14. Using scan tool MB991958, check data list item 06: Brake Switch. 
    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.
      Fig 19: Connecting Scan Tool To Data Link Connector
      G00809767Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Set scan tool MB991958 to data reading mode.
      • Item 06, Brake Switch.
        • When the brake pedal is depressed, the display on scan tool MB991958 should be "ON".
        • When the brake pedal is released, the display on scan tool MB991958 should be "OFF".
    4. Turn the ignition switch to the "LOCK" (OFF) position.
    5. Disconnect scan tool MB991958.

    Q: Is the switch operating properly? 

    1. YES:  Go to  Step 22.
    2. NO:  Go to Step 15.
  15. STEP 15. Measure the terminal voltage at ECM connector C-135 < M/T > or PCM connector C-136 < A/T >. 
    1. Do not disconnect ECM connector C-135 < M/T > or PCM connector C-136 < A/T >.
      Fig 20: Identifying Connectors C-135, C-136
      G00809768Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Measure the voltage between ECM connector C-135 < M/T > terminal 54 or PCM connector C-136 < A/T > terminal 54 and ground by backprobing.
      • When the brake pedal is depressed, the voltage should measure battery positive voltage (approximately 12 volts).
      • When the brake pedal is released, the voltage should measure 1 volt or less.
        Fig 21: Measuring Voltage Between ECM Connector C-135 Or PCM Connectior C-136 and Ground
        G00809769Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    4. Turn the ignition switch to the "LOCK" (OFF) position.

    Q: Is the measured voltage battery positive voltage (approximately 12 volts) when the brake pedal is depressed and 1 volt or less when the brake pedal is released? 

    1. YES:  Go to  Step 21.
    2. NO:  Go to Step 16.
  16. STEP 16. Check the stoplight switch. 
    1. Remove the stoplight switch.
    2. Connect an ohmmeter to the stoplight switch between terminals 3 and 4.
      Fig 22: Connecting Ohmmeter
      G00809770Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Check for continuity between the terminals when the plunger of the stoplight switch is pushed in and when it is released.
      Fig 23: Checking Continuity
      G00809771Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    4. The stoplight switch is operating properly if the circuit is open between terminals 3 and 4 when the plunger is released, and if resistance value is less than 2 ohms between terminals 3 and 4 when the plunger is pushed in to a depth of within 4.5 mm (0.18 inch) from the outer case edge surface.

    Q: Is the stoplight switch between terminals 3 and 4 still open circuit when the plunger is released, and resistance value is less than 2 ohms even with the plunger is pushed in? 

    1. YES:  Install the stoplight switch . Then go to Step 17.
    2. NO:  Replace the stoplight switch . Then go to  Step 23.
  17. STEP 17. Check ECM connector C-135 < M/T > or PCM connector C-136 < A/T >, intermediate connector C-108 and stoplight switch connector C-102 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 
    Fig 24: Identifying Connector C-135 (M/T), C-136 (A/T)
    G00809772Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 25: Identifying Connector C-108
    G00809773Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 26: Identifying Connector C-102
    G00809774Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are there connectors and terminals in good condition? 

    1. YES:  Go to Step 18.
    2. NO:  Repair or replace the damaged components. Then go to  Step 23.
  18. STEP 18. Check the harness wire between ECM connector C-135 < M/T > terminal 54 or PCM connector C-136 < A/T > terminal 54 and stoplight switch connector C-102 terminal 3 for damage. 
    Fig 27: Identifying Connectors: C-135 (M/T), C-136 (A/T)
    G00809775Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 28: Identifying Connector C-102
    G00809776Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are there harness wires in good condition? 

    1. YES:  Go to Step 19.
    2. NO:  Repair the damaged harness wire. Then go to  Step 23.
  19. STEP 19. Check stoplight switch connector C-102 and intermediate connector C-111 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 
    Fig 29: Identifying Connector C-102
    G00809777Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 30: Identifying Connector C-111
    G00809778Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are there connectors and terminals in good condition? 

    1. YES:  Go to Step 20.
    2. NO:  Repair or replace the damaged components. Then go to  Step 23.
  20. STEP 20. Check the harness wire between stoplight switch connector C-102 terminal 4 and ground for damage. 
    Fig 31: Identifying Connector C-102
    G00809779Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 32: Checking Harness Wire
    G00809780Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Is the harness wire in good condition? 

    1. YES:  Go to Step 21.
    2. NO:  Repair the damaged harness wire. Then go to  Step 23.
  21. STEP 21. Using scan tool MB991958, check data list item 06: Brake Switch. 
    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.
      Fig 33: Connecting Scan Tool MB991958 To Data Link Connector
      G00809781Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Set scan tool MB991958 to data reading mode.
      • Item 06, Brake Switch.
        • When the brake pedal is depressed, the display on scan tool MB991958 should be "ON".
        • When the brake pedal is released, the display on scan tool MB991958 should be "OFF".
    4. Turn the ignition switch to the "LOCK" (OFF) position.
    5. Disconnect scan tool MB991958.

    Q: Is the switch operating properly? 

    1. YES:  Go to Step 22.
    2. NO:  Replace the ECM < M/T > or PCM < A/T > [Refer to ENGINE CONTROL MODULE (ECM) AND POWERTRAIN CO ]. Then go to  Step 23.
  22. STEP 22. Using scan tool MB991958, read the diagnostic trouble codes. 
    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.
      Fig 34: Connecting Scan Toll MB991958 To Data Link Connector
      G00809782Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Set scan tool MB991958 to read the diagnostic trouble codes.
    4. Turn the ignition switch to the "LOCK" (OFF) position.
    5. Disconnect scan tool MB991958.

    Q: Is DTC 22 set? 

    1. YES:  Replace the ECM < M/T > or PCM < A/T > [Refer to ENGINE CONTROL MODULE (ECM) AND POWERTRAIN CO ]. Then go to Step 23.
    2. NO:  It can be assumed that this malfunction is intermittent (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
  23. STEP 23. Using scan tool MB991958, read the diagnostic trouble codes. 
    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.
      Fig 35: Connecting Scan Tool MB991958 To Data Link Connector
      G00809783Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Set scan tool MB991958 to read the diagnostic trouble codes.
    4. Turn the ignition switch to the "LOCK" (OFF) position.
    5. Disconnect scan tool MB991958.

    Q: Is DTC 22 set? 

    1. YES:  Return to  Step 1.
    2. NO:  The procedure is complete.
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