What does it mean?
B1545 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Occupant classification-ECU for power supply circuit .
Symptoms
- Seat moves by itself or will not stop when the switch is released
- Seat runs to its end stop and the motor stalls audibly
- Seat or memory fuse blows repeatedly
- Memory recall and easy-entry functions stop working
- The code returns as soon as the ignition is switched on, without touching the switch
- Airbag warning lamp on where the code refers to the occupant classification supply
Likely causes
- Seat direction switch wire chafed against the seat motor supply under the seat, feeding battery voltage into the input
- Liquid spillage inside the switch bridging a powered contact to the signal contact
- Aftermarket seat heater, 12 V socket or audio wiring tapped into the seat loom
- Seat direction switch shorted internally, holding the input high
- Damaged output or input driver inside the seat module
- Connector terminal displaced and touching a powered pin
- On applications where this code refers to the occupant classification system, an overvoltage or short on the OCS control unit supply circuit
How to fix it
- With the switch released, back-probe the input at the module and look for battery voltage where the reference voltage should be
- Unplug the switch and repeat the measurement to decide between the switch and the harness
- Inspect the loom along the seat rail and under the seat frame where the motor supply runs next to the switch wires
- Check every aftermarket tap in the seat area and disconnect it before retesting
- Confirm the seat motor supply is not back-feeding through a damaged connector
- Repair the shorted section and secure the loom clear of the rail travel; replace the switch only if it measures shorted
- Where the code refers to occupant classification, measure the control unit supply voltage against specification and inspect its fuse and feed wire