Inspection Procedure 13: Seat belt reminder function does not work normally: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB992006: Extra Fine Probe

1. STEP 1. Using scan tool (M.U.T.-III), diagnose the CAN bus line 
   CAUTION: To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
   1. Connect scan tool (M.U.T.-III). 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? 

   1. YES:  Go to Step 2.
   2. NO:  Repair the CAN bus line (Refer to TROUBLESHOOTING ).
2. STEP 2. Using scan tool (M.U.T.-III), read the SRS diagnostic trouble code. 

   Check if DTC is stored in the SRS-ECU.

   Q: Is the DTC stored? 

   1. YES:  Diagnose the SRS-ECU (Refer to TROUBLESHOOTING ).
   2. NO:  Go to Step 3.
3. STEP 3. Check the seat belt switch. 

   Refer to FRONT SEAT BELT .

   Q: Is the check result normal? 

   1. YES:  Go to Step 4.
   2. NO:  Replace the seat belt switch.
4. STEP 4. Resistance measurement at the seat belt switch (driver's side) connector 
   1. Disconnect the connector, and measure at the wiring harness side.
   2. Measure the resistance between the seat belt switch (driver's side) connector and ground.

      OK: The resistance should be 2 ohms or less. 

   Q: Is the check result normal? 

   1. YES:  Go to  Step 6.
   2. NO:  Go to Step 5.
5. STEP 5. Check of open circuit in ground line between seat belt switch (driver's side) connector and ground. 

   Q: Is the check result normal? 

   1. YES:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
   2. NO:  Repair the connector(s) or wiring harness.
6. STEP 6. Check of short to power supply circuit in SBDS line between combination meter connector and seat belt switch (driver's side) connector. 

   Q: Is the check result normal? 

   1. YES:  Go to Step 7.
   2. NO:  Repair the connector(s) or wiring harness.
7. STEP 7. Check of short to power supply, and open circuit in BWLP line between combination meter connector and hazard indicator assembly connector. 

   Q: Is the check result normal? 

   1. YES:  Go to Step 8.
   2. NO:  Repair the connector(s) or wiring harness.
8. STEP 8. Retest the system. 

   The seat belt reminder function should work normally.

   Q: Is the check result normal? 

   1. YES < The seat belt reminder function works normally. >:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
   2. NO < Tone alarm sounds do not sound. >:  Replace the combination meter.
   3. NO < The indicator (driver's side) does not illuminate. >:  Replace the combination meter.
   4. NO < The indicator (passenger's side) does not illuminate. >:  Replace the hazard indicator assembly, and then go to Step 9.
9. STEP 9. Retest the system. 

   The seat belt reminder function should work normally.

   Q: Is the check result normal? 

   1. YES:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
   2. NO:  Replace the combination meter.