Airbag control unit with part number 9145402-01

What does the airbag control unit 9145402-01 do?

The airbag control unit 9145402-01 is the central control unit of the restraint system (SRS) in BMW. It evaluates the signals from the crash sensors and decides within milliseconds in an accident which airbags and seatbelt pretensioners to trigger. It monitors the system continuously and reports faults via the airbag warning light.

The evaluation runs constantly in the background, even during calm driving. The unit checks sensors, wiring and output stages of the trigger units and stores every deviation in the fault memory.

After an accident the unit stores crash data and locks itself. This information is among the most important details when the cause of a defect is to be established.

Why does the control unit 9145402-01 fail?

The unit most often fails because crash data was stored after an accident, even if no airbag was triggered. A normal diagnostic tool cannot erase this data. Other causes are ageing electronic components, cold solder joints, moisture or corrosion on plug connections, and voltage spikes, for example from a weak battery or jump-starting.

Stored crash data is particularly significant for fault finding. It stays in the memory even if the vehicle continues to run inconspicuously and no airbag visibly deployed.

The other causes lie in the electronics or the connections. Solder joints can give way over the years, and moisture or salt affect plug contacts. Such fluctuations place additional strain on the electronics.

How can you tell that the 9145402-01 is defective?

A defect shows up at the airbag warning light in the instrument cluster, which lights up permanently or intermittently.

• Airbag warning light stays on permanently
• Airbag warning light comes on intermittently
• Error message in the instrument cluster
• No connection to the diagnostic tool
• Fault memory cannot be cleared

The warning light indicates the fault itself. Take the warning seriously and have the vehicle checked rather than ignoring it.

Which vehicles is the 9145402-01 fitted in?

These vehicles are equipped with the 9145402-01: BMW 5 Series E61 LCI Touring (2007-2010), E61 Touring (2004-2007), E60 LCI Saloon (2007-2010) and E60 Saloon (2003-2007); BMW M5 E61 Touring (2007-2010).

The overview of the assigned models follows here:

• BMW 5 Series E61 LCI Touring (2007-2010)
• BMW M5 E61 Touring (2007-2010)
• BMW 5 Series E61 Touring (2004-2007)
• BMW 5 Series E60 LCI Saloon (2007-2010)
• BMW 5 Series E60 Saloon (2003-2007)

Before you remove the unit, compare the label with this page. This alone confirms that you have the correct control unit in front of you. It does not establish a cause. Have the fault memory read out, because only the log shows whether the control unit is defective or a plug or cable is responsible.

For the same vehicles, we also repair control units with the part numbers 31911421401V, 319145401011, 65 77 9 118 749 01, 65 77 911 4214-01, 65.77 9172018-01, 65.77-6946384.

How does the repair of the 9145402-01 work?

Have the fault memory read out first and enclose the log. Then disconnect the battery and only then remove the control unit. Next, create a repair order online and send the well-packed unit in. Processing at Airbag24, i.e. inspection, repair and function test, usually takes 3–4 working days.

The sequence protects you while working on the vehicle. Without a read-out fault memory and a disconnected battery, you do not remove the unit.

At Airbag24 the unit is first inspected on the test bench. Defective components are then repaired, stored crash data is erased and a function test is carried out. After that, the unit is returned to you.

Our repairs come with 2 years' statutory liability for defects. The repaired control unit comes back with all vehicle data and is ready for use as soon as it is refitted — no coding or programming is required.

How does the control unit 9145402-01 get to Airbag24?

You send the control unit to Airbag24 as a parcel, or you commission a UPS collection for an extra charge. After the repair, the unit comes back to you by UPS.

The printed repair order belongs in the parcel. Pack the unit shockproof so that it survives the journey undamaged.