B1540

DTC B1540: Occupant classification-ECU malfunction
DTC B1541: Occupant classification-ECU calibration malfunction
DTC B1542: Occupant classification sensor (S1) malfunction
DTC B1543: Occupant classification sensor (S2) malfunction
DTC B1558: Occupant classification-ECU ID-cord malfunction

CAUTION: If DTCs are set in the occupant classification-ECU, always diagnose the CAN main bus line.

B1540 - B1558:

DTC SET CONDITIONS
- These DTC are set when a fault is detected in the occupant classification-ECU. The most likely causes for this code to be set are shown in the

TROUBLESHOOTING HINTS
- Malfunction of the occupant classification-ECU

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

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 Information Bus, 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: Are DTCs B1540, B1541, B1542, B1543,or B1558 set?

YES: Replace the front seat slide adjuster (Refer to front seat assembly).

NO: There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions).