DTC 33: Stoplight Switch Syst: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB991958: Scan Tool (MUT-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827: MUT-III USB Cable
  • MB991911: MUT-III Main Harness B (Vehicles without CAN communication system)
• MB991529: Diagnostic Trouble Code Check Harness

1. STEP 1. Check the stoplight operation.

   Q: Does the stoplight come on and go out correctly? 

   • YES:  Go to  Step 4 .
   • NO:  Go to Step 2.
2. STEP 2. Check the stoplight switch installation condition.

   Q: Is the stoplight switch installed properly? 

   • YES:  Go to Step 3.
   • NO:  Repair it and then go to  Step 7 .
3. STEP 3. Check the stoplight switch continuity.
   1. Remove the stoplight switch. (Refer to BRAKE PEDAL .)
   2. Connect an ohmmeter to stoplight switch terminals 1 and 2, and check whether there is continuity when the plunger of the stoplight switch is pushed in and when it is released.
   3. The stoplight switch is in good condition if there is no continuity when the plunger is pushed in to a depth of within 4 mm (0.16 inch) from the outer case edge surface, and if there is continuity when it is released.

   Q: Is the stoplight switch continuity incorrect? 

   • YES:  Replace it and then go to  Step 7 .
   • NO:  Check the stoplight circuit and repair and then go to  Step 7 .
   Fig 1: Checking Stoplight Switch Continuity

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. STEP 4. Using scan tool MB991958, check data list.
   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. Set scan tool MB991958 to data reading mode.
      • Item 33: Stoplight switch
      • ON with brake pedal stepped down.
      • OFF with brake pedal released.

   Q: Is the stoplight switch input normal? 

   • YES:  This malfunction is intermittent. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS .
   • NO:  Go to Step 5.
   Fig 2: Connecting Scan Tool MB991958 To Data Link Connector

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
5. STEP 5. Check the stoplight switch circuit at ABS-ECU connector B-118.
   1. Disconnect connector B-118 and measure at the harness side.
   2. Turn the stoplight switch ON.
   3. Measure the voltage between terminal 3 and ground. It should be approximately 12 volts (battery positive voltage).

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

   • YES:  Replace the hydraulic unit (integrated with ABS-ECU) and then go to  Step 7 .
   • NO:  Go to Step 6.
   Fig 3: Checking Voltage Between Terminal 3 And Ground

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
6. STEP 6. Check the harness wire between ABS-ECU connector B-118 terminal 3 and stoplight switch connector C-102 terminal 1.
   Fig 4: Identifying ABS-ECU Connector B-118

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   Fig 5: Identifying Stoplight Switch Connector C-102

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   NOTE: After inspecting intermediate connectors C-105, C-124 and stoplight switch connector C-102, inspect the wire. If intermediate connectors C-105, C-124 and stoplight switch connector C-102 are damaged, repair or replace them. Refer to HARNESS CONNECTOR INSPECTION . If the connector has been repaired or replaced, go to Step 7.

   Q: Is the harness wire between ABS-ECU connector B-118 terminal 3 and stoplight switch connector C-102 terminal 1 damaged? 

   • YES:  Repair it and then go to Step 7.
   • NO:  Go to Step 7.
   Fig 6: Identifying Intermediate Connectors C-105 And C-124

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
7. STEP 7. Recheck for diagnostic trouble code.

   Q: Does DTC 33 reset? 

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