DTC B1B8C: Seat Slide Sensor Circuit Performance: Diagnosis

Required Special Tools: 

• MB991958 Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V. C. I).
  • MB991827 M.U.T.-III USB Cable
  • MB991910 M.U.T.-III Main Harness A (Vehicles with CAN communication system)

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  ".
   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 ).

   Fig 1: Connecting Special Tool MB991910 To Data Link Connector

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Recheck for diagnostic trouble code. 

   Check again if the DTC is set.

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

   Q: Is the DTC set? 

   YES  : Go to Step 3.

   NO  : There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).

3. STEP 3. Check the occupant classification-ECU connector D-39-2, front seat assembly D-39 and seat slide sensor D-32 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is the occupant classification-ECU connector D-39-2, front seat assembly D-39 and seat slide sensor D-32 in good condition? 

   YES  : Go to Step 4.

   NO  : Repair or replace the component(s) (Refer to HARNESS CONNECTOR INSPECTION ).

4. STEP 4. Check the wiring harness between the occupant classification-ECU connector D-39-2 (terminal 27 and 29) and the seat slide sensor D-32 (terminal 2 and 1). 

   Q: Check for continuity between occupant classification-ECU connector D-39-2 (terminal 27 and 29) and the seat slide sensor D-32 (terminal 2 and 1)? 

   YES  : Go to Step 5.

   NO  : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.

5. STEP 5. Recheck for diagnostic trouble code. 

   Check again if the DTC is set to the occupant classification-ECU.

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

   Q: Is the DTC set? 

   YES  : Replace the slide adjuster (LH) (Refer to FRONT SEAT ASSEMBLY ).

   NO  : There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).