Air Pocket for BMW Turbo
This bulletin applies to 2015 BMW 650i Gran Coupe Base vehicles equipped with a turbocharged engine. The check engine light may come on after a hot engine restart. When this happens, the engine may have a longer cranking time before starting. The following faults may be stored in the DME:
20A504 (turbocharger coolant pump, actuation: Line disconnection)
133011 (Valvetronic supply voltage malfunction)
133013 (Valvetronic 2 supply voltage malfunction)
1F0515 (Valvetronic supply voltage line disconnection)
1F050F (Valvetronic 2 supply voltage line disconnection)
The problem is caused by air in the cooling system which tends to collect in the area of the turbocharger electric coolant pump. When the engine is shut off, the turbocharger coolant pump impeller continues to spin down in the air pocket. This subsequently generates a voltage that is fed back to the DME, causing the faults to be stored.
Inspect and bleed the cooling system thoroughly and ensure that all connections are tight. Replace the turbo cooling lines if needed.