The B109C15 code is a manufacturer-specific DTC, which means it's defined by Land Rover for its own vehicles. It is categorized under the "Body" control module (indicated by the prefix) and is directly related to the electrical circuit of the front courtesy light (also known as the front interior lamp).
If the code points to the luxury seating circuits, the heated or cooled seat functions may shut off automatically a few seconds after activation as a safety measure. Section 4: Advanced Step-by-Step Troubleshooting Workflow
: Corroded or broken wires within the door harness can create an "open circuit" state. Loose Connections land rover b109c15 extra quality
Perform this simple test:
This is a notorious culprit in luxury SUVs. Clogged sunroof drains, leaking windshield seals, or heavy off-roading through deep water can allow moisture to pool in the footwells. Land Rover often places critical wiring junctions and fuse boxes in these lower areas, leading to corrosion and open circuits. 3. Blown Fuses or Corroded Relays The B109C15 code is a manufacturer-specific DTC, which
The "15" suffix in B109C15 is a sub-type code that points toward a circuit failure. Most often, this is caused by a pinched wire in the overhead console or a blown internal driver in the lighting module. To address this with extra quality standards, technicians recommend a thorough "pin-out" test. This involves checking the resistance and voltage at the specific connector pins rather than simply swapping out bulbs.
The code B109C15 is often accompanied by the description: . This technical description points to a few key potential issues within the electrical circuit that powers your front interior light: Land Rover often places critical wiring junctions and
Monitor live data in the DDM/PDM to verify if the module is sending power to the lamps. Making sense of fault codes? | LandyZone - Land Rover Forum