DTC B1B8D: Seat Slide Sensor Open Circuit: Diagnosis

WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

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)

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.
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 ).
STEP 3. Check the harness for open circuit between occupant classification-ECU connector D-39-2 (terminal No. 27 and 29) and the seat slide sensor connector D-32 (terminal No. 2 and 1).
1. Disconnect occupant classification-ECU connector D-39-2 and seat slide sensor connector D-32.
  CAUTION: Do not insert a test probe into the terminal from its front side directly, as the connector contact pressure may be weakened.
2. Check for continuity between the following terminals. It should be less than 2 ohms.
  - Occupant classification-ECU connector D-39-2 (terminal No. 27) and the seat slide sensor connector D-32 (terminal No. 2)
  - Occupant classification-ECU connector D-39-2 (terminal No. 29) and the seat slide sensor connector D-32 (terminal No. 1)
    
    Fig 2: Checking Continuity Between Classification-ECU D-39-2 And Seat Slide Sensor Connector D-32
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Q: Does continuity exist?

YES : Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1B8D sets, replace the slide adjuster (LH) (Refer to FRONT SEAT ASSEMBLY ).

NO : Repair the harness wires between occupant classification-ECU connector D-39-2 and seat slide sensor connector D-32. Then go to Step 4.
STEP 4. 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 B1B8D 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 ).