Symptom Procedures: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB992006: Extra Fine Probe

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. Refer to "HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ."
   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? 

   YES:  Go to Step  2.

   NO:  Repair the CAN bus line (Refer to DIAGNOSIS ).

2. STEP 2. Using scan tool MB991958, read for SRS diagnostic trouble code. 

   Check the DTC is set in the SRS.

   Q: Is the DTC set? 

   YES:  Troubleshoot the SRS (Refer to INTRODUCTION TO CRUISE CONTROL SYSTEM DIAGNOSIS ).

   NO:  Go to Step  3.

3. STEP 3. Check seat belt switch (driver's side) connector D-33 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is seat belt switch (driver's side) connector D-33 in good condition? 

   YES:  Go to Step  4.

   NO:  Repair the defective connector.

4. STEP 4. Check the seat belt switch. 

   Refer to Front Seat Belt REMOVAL SERVICE POINT .

   Q: Is the check result normal? 

   YES:  Go to Step  5.

   NO:  Replace the seat belt switch.

5. STEP 5. Check the ground circuit to the seat belt switch (driver's side). Test at seat belt switch (driver's side) connector D-33. 
   1. Disconnect the connector, and measure at the wiring harness side.
   2. Measure the resistance value between terminal 1 and ground.
   • The resistance should be 2 ohms or less.

   Q: Is the measured resistance 2 ohms or less? 

   YES:  Go to Step  7.

   NO:  Go to Step  6.

   Fig 1: Measuring Resistance Value Between Terminal 1 And Ground

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
6. STEP 6. Check the wiring harness between seat belt switch (driver's side) connector D-33 (terminal 1) and ground. 

   Check the ground wire for open circuit.

   Q: Is the wiring harness between seat belt switch (driver's side) connector D-33 (terminal 1) and ground in good condition? 

   YES:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).

   NO:  Repair the wiring harness.

7. STEP 7. Check combination meter connector C-203 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is combination meter connector C-203 in good condition? 

   YES:  Go to Step  8.

   NO:  Repair the defective connector.

8. STEP 8. Check the wiring harness between combination meter connector C-203 (terminal 5) and seat belt switch <driver's side> connector D-33 (terminal 2). 
   • Check the input line for open and short circuit.
   NOTE: Also check intermediate connector C-26 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-26 is damaged, repair or replace the damaged component(s) as described in HARNESS CONNECTOR INSPECTION .

   Q: Is the wiring harness between combination meter connector C-203 (terminal 5) and seat belt switch <driver's side> connector D-33 (terminal 2) in good condition? 

   YES:  Go to Step  9.

   NO:  Repair the wiring harness.

9. STEP 9. Check hazard indicator assembly connector C-246 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is hazard indicator assembly connector C-246 in good condition? 

   YES:  Go to Step  10.

   NO:  Repair the defective connector.

10. STEP 10. Check the wiring harness between combination meter connector C-203 (terminal 19) and hazard indicator assembly connector C-246 (terminal 3). 
    • Check the input line for open and short circuit.

    Q: Is the wiring harness between combination meter connector C-203 (terminal 19) and hazard indicator assembly connector C-246 (terminal 3) in good condition? 

    YES:  Go to Step  11.

    NO:  Repair the wiring harness.

11. STEP 11. Retest the system. 

    The seat belt reminder function should work normally.

    Q: Is the check result normal? 

    YES <The seat belt reminder function works normally.>:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).

    NO <Tone alarm sounds do not sound.>:  Replace the combination meter.

    NO <The indicator (driver's side) does not illuminate.>:  Replace the combination meter.

    NO <The indicator (passenger's side) does not illuminate.>:  Replace the hazard indicator assembly.