B1B8C
DTC B1B8C: Seat Slide Sensor Circuit PerformanceSeat Slide Sensor Circuit (Part 1):
Seat Slide Sensor Circuit (Part 2):
CAUTION: If DTC B1B8C is set in the occupant classification-ECU, always diagnose the CAN main bus lines.
CIRCUIT OPERATION
- The seat slide sensor sets the current value Hi or Low determined by the seat position.
- The occupant classification-ECU determines the seat position according to the current value from the seat slide sensor.
DTC SET CONDITION
The DTC is set when the seat slide sensor output current is not within the specified range.
TROUBLESHOOTING HINTS
- The seat slide sensor may be defective.
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
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)
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." Scan Tool Connecting
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 Controller Area Network, Diagnosis).
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 general (Body and Chassis), How to Cope with Intermittent Malfunction).
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 general (Electrical), Harness Connector Inspection.
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.
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 Interior, Front Seat Assembly.
NO: There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to general (Body and Chassis), How to Cope with Intermittent Malfunction).