Original BMW Alarm System Switch for BMW 525i, 528i, 530i, 540i, M5, and Z4 (1997–2008)

The Original BMW alarm system switch is the hood or trunk contact that tells the factory alarm when that lid is opened, and it fits the E39 525i, 528i, 530i, 540i, and M5 plus the 2003–2008 BMW Z4. BMW names it simply switch, and it weighs 12 g. This is the current number, in production since June 2006. It replaced the earlier switch 61-31-4-158-205, and BMW marks that change as interchangeable retrospectively, so it serves cars built long before 2006. It is made in Poland.

A 24-month parts warranty covers this Original BMW Part.

An alarm switch like this one is located under the hood or in the trunk and feeds the factory alarm. The same switch serves both the E39 5 Series and the Z4 E85 and E86. Three numbers point to this part: the current 61-31-9-119-057, the superseded 61-31-4-158-205, and a related reference number, 61-31-8-374-745.

Technical Details

• Manufacturer: BMW, sold as an Original BMW part
• Part number: 61-31-9-119-057
• BMW designation: switch, alarm system
• Location: under the hood or in the trunk
• Supersedes 61-31-4-158-205, interchangeable retrospectively
• Also cross-references 61-31-8-374-745
• Weight: 12 g (0.42 oz)
• Production start: June 2006
• Sold as: one piece
• Country of manufacture: Poland
• Warranty: 24 months on parts

Common Questions

My car has the old 61-31-4-158-205 switch. Will this replace it?
Yes. BMW supersedes that number with this one and marks it as interchangeable retrospectively.

Is this the hood switch or the trunk switch?
It is the alarm switch used under the hood or in the trunk on the models shown.

Where is it made?
Poland.

Fitment & Compatibility

Use the fitment table below to confirm year, make, model, submodel, and any notes tied to your exact vehicle. Pay close attention to engine, chassis, position, and option-specific details before ordering. Send your VIN and PMB Performance will confirm the fit, drawing on more than 20 years in the trade.