BMW X5 E70 factory Webasto does not start or does not heat
Why does the Webasto on an X5 E70 not start?
The most common cause in freezing weather is a weak battery that cannot start the heater in the cold. Another cause is the heater locking out after a fault. Unlocking it requires a brand-specific diagnostic tool; a simple hobbyist code reader is usually not enough.
What does fault code 009C87 mean?
The code points to the auxiliary heater, that is the Webasto, but it does not tell you the specific fault. Troubleshooting therefore has to be done through the heater's components: power supply, flame sensor, combustion chamber and valve.
What should I do if the Webasto shuts off or stops working?
A dirty flame sensor or glow plug can prevent operation. The combustion chamber can often be cleaned. The Webasto bolts are thread-locked at the factory and break easily, so it is worth heating the housing before undoing the bolts. If the combustion chamber connectors have only one white connector, the chamber has no solenoid valve.