Airbag control unit with part number 46813508

What does the airbag control unit 46813508 do?

The airbag control unit 46813508 is the control centre of the SRS restraint system in vehicles of Fiat. It evaluates the crash sensors, determines within milliseconds which airbags and seatbelt pretensioners are triggered, and monitors the system continuously. If a fault occurs, it is shown via the airbag warning light.

The evaluation follows fixed rules: the sensor signals are constantly compared with threshold values.

After an accident, the unit stores crash data and locks itself. This data stays in the memory and is important for fault finding.

Why does the control unit 46813508 fail?

Most often the cause is crash data stored after an accident, even if no airbag fired. Ordinary diagnostic tools cannot remove it. Other causes are ageing electronic components, dry solder joints, moisture and corrosion on connectors, and voltage spikes, for example from a weak battery or a jump start.

Over the years, electronic components wear out. Dry solder joints create only an unsteady connection.

Moisture and corrosion attack plug connections. Voltage spikes put additional strain on the unit.

How can you tell that the 46813508 is defective?

A defect shows itself through the airbag warning light in the instrument cluster, which lights up permanently or intermittently. A fault message also appears, the diagnostic tool cannot reach the control unit, and the fault memory cannot be cleared. In such a case, airbags and seatbelt pretensioners may fail to deploy in an emergency.

The most important signs at a glance:

• Airbag warning light that lights up permanently or intermittently
• Fault message in the instrument cluster
• Diagnostic tool without connection to the control unit
• Fault memory that cannot be cleared

With these signs, airbags and seatbelt pretensioners may fail to deploy in an emergency. Please have the system checked promptly.

Which vehicles is the 46813508 fitted in?

The vehicles in which this control unit is fitted are listed below. The control unit 46813508 is fitted in these vehicles: Fiat Multipla 186 (1999-2004) and 186 Facelift (2004-2008).

Here are the vehicles at a glance:

• Fiat Multipla 186 (1999-2004)
• Fiat Multipla 186 Facelift (2004-2008)

Compare the part number on the label of the removed unit with this page. That tells you whether you have the correct unit, but the comparison says nothing more. Have the fault memory read out beforehand. Only this log shows whether the control unit is defective or whether a connector or a cable is the cause.

For the same vehicles, we also repair control units with the part numbers 51759726, 5WK42818.

How does the repair of the 46813508 work?

First have the fault memory read out and the log enclosed; then disconnect the battery and only then remove the control unit. Next, create the repair order online and send in the packed unit. Airbag24 tests it on the test bench, repairs defective components, clears stored crash data and carries out a function test.

The sequence is binding for safety reasons, especially disconnecting the battery before removal.

Airbag24 needs 3–4 working days as a rule for testing, repair and the function test.

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 46813508 get to Airbag24?

You send the unit to Airbag24 as a parcel, or you book a UPS collection for an extra charge. After the repair, UPS brings the unit back to you.

Pack the control unit so that it withstands knocks well, and enclose the printed repair order.