Airbag control unit with part number A6394460442

What does the airbag control unit A6394460442 do?

The airbag control unit A6394460442 regulates the SRS restraint system for Mercedes-Benz as the central unit. It checks the crash sensors, decides in a crash within milliseconds which airbags and seatbelt pretensioners are triggered, and monitors the system without interruption.

The manufacturer number Bosch 0285001448 is additionally printed on the housing.

The fault is indicated via the airbag warning light. After an accident, the control unit stores crash data and locks itself.

Why does the control unit A6394460442 fail?

The most common cause is crash data stored after an accident, even if no airbag has fired; with a normal diagnostic tool it cannot be erased. Further causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

The crash data stays stored until it is specifically removed. The unit can therefore show the fault even if the accident is long past.

The other causes act over a longer period: solder joints become unreliable, plug connections corrode, and a weak battery or a jump start loads the electronics.

How can you tell that the A6394460442 is defective?

A defect shows itself through the airbag warning light, through messages in the instrument cluster and through a diagnostic tool that finds no control unit.

• Airbag warning light lit permanently or intermittently
• Error message in the instrument cluster
• Diagnostic tool gets no connection to the control unit
• Fault memory cannot be cleared

In an emergency, airbags and seatbelt pretensioners may then fail to deploy. Take such signs seriously and have them checked promptly.

Which vehicles is the A6394460442 fitted in?

The A6394460442 is fitted in these vehicles: Mercedes-Benz Vito W639 (2003-2014); Mercedes-Benz Viano W639 (2003-2014); Mercedes-Benz V-Class W639 (2003-2014).

The vehicles are listed below.

• Mercedes-Benz Vito W639 (2003-2014)
• Mercedes-Benz Viano W639 (2003-2014)
• Mercedes-Benz V-Class W639 (2003-2014)

First compare the part number on the label of the removed unit with this page; that only confirms that it is the right unit. Then have the fault memory read out, because the result shows whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 0285010349, 285001448, 285001449, 285010033, 285010054, 285010224.

How does the repair of the A6394460442 work?

Have the fault memory read out and enclose the log. Then disconnect the battery and only afterwards remove the control unit. Create a repair order online and send the unit off well packed. Airbag24 usually needs 3–4 working days for checking, repairing and testing.

The order is binding, because it keeps safety in view at every step.

Airbag24 checks the unit on the test bench, replaces defective components, erases stored crash data and carries out a function test. Afterwards your own unit is sent back 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 A6394460442 get to Airbag24?

You can send the parcel yourself, or book a UPS collection for an extra charge. The return after the repair is made by UPS.

The printed repair order goes into the parcel; the unit should be packed shockproof.