CAR SEAT HEATER BMW X5 (F15, F85) (06.2012 - 07.2018)

On the 2015 BMW X5, problems with seat heating may be related to:
- A faulty temperature sensor – it may give incorrect readings, causing overheating or no heating.
- Damage to the heating elements – they may fail over time.
- A failure in the control unit – there may be errors in the electronics that affect the operation of the heating.
It is recommended to check the temperature sensor and wiring

The issues with your 2015 BMW X5’s seat heater—either not warming up at all or getting excessively hot—are known problems among owners and can be caused by a few common faults:

Possible Causes
Broken or damaged heating element wires: The heating mats inside the seat covers have woven wires that can break, causing the heater to either fail or overheat. If a wire breaks, the control unit may shut the heater off or cause erratic heating.

Faulty thermistor: The thermistor regulates the seat temperature. A malfunctioning thermistor can cause the seat to get too hot or not warm properly.

Connector or fuse issues: Loose connectors or blown fuses related to the seat heating system can cause intermittent or no heating.

Seat heating module faults: Internal faults in the seat heater control modules, especially in rear seats, can disrupt the LIN bus communication and cause heater failure.

Control button or unit malfunction: Sometimes the seat heater control switch itself can fail, causing the heater to turn off prematurely or not engage properly.

Diagnostic and Fix Tips
Check fuses and connectors: Start with inspecting the fuse and connector integrity for the seat heater circuit.

Test resistance of heating elements: Using a multimeter, check the resistance across the heating element wires (typically 2-3 ohms). An open circuit reading indicates a broken wire in the heating mat.

Scan for fault codes: Use a BMW diagnostic tool (like ISTA) to read seat heater fault codes and identify faulty modules.

Replace heating mat or seat covers: If the heating element or thermistor is damaged, the seat cover often needs replacement since these components are integrated into it.

Professional repair: Given the complexity and cost, many owners opt for professional repair or replacement of seat heating modules or seat covers.

Your symptoms are consistent with common BMW X5 seat heater issues caused by broken heating element wires, faulty thermistors, or control module faults. Start by checking fuses and connectors, then test the heating element resistance. If damaged, replacing the seat heating mat or seat cover is usually necessary. Professional diagnosis with BMW ISTA software can pinpoint module faults. Repair costs vary but typically involve seat disassembly and component replacement.

If you want to try DIY, be very careful removing seat covers to avoid damage. Otherwise, a BMW specialist or experienced workshop is recommended for reliable repair.