Airbag control unit with part number 985102045R

What does the airbag control unit 985102045R do?

The airbag control unit 985102045R coordinates the restraint system (SRS) in Smart. It processes the measured values from the crash sensors, determines in an accident which airbags and seatbelt pretensioners are triggered, and shows faults on the airbag warning light.

The unit monitors the system constantly, and faults end up in the fault memory. After an accident, it stores crash data and locks itself.

Why does the control unit 985102045R fail?

The most common cause is crash data stored in the control unit 985102045R after an accident, even if no airbag was triggered. Further causes are aged electronic components, cold solder joints, moisture and corrosion, and voltage spikes.

An ordinary diagnostic tool cannot erase this crash data. The statement that it can be erased means exactly this: Airbag24 removes it during the repair.

Moisture attacks the contacts, and corrosion at plug connections can disrupt the flow of current. Voltage spikes arise, for example, with a weak battery or jump leads and put strain on the electronics.

How can you tell that the 985102045R is defective?

The airbag warning light in the instrument cluster lights up on the 985102045R permanently or intermittently, and a fault message appears in the instrument cluster. In addition, a diagnostic tool cannot establish a connection to the control unit, and the fault memory cannot be cleared.

If the control unit is defective, airbags and seatbelt pretensioners may fail to deploy in an emergency.

The warning light makes the fault visible. If it comes on, have the system checked promptly.

Which vehicles is the 985102045R fitted in?

The airbag control unit 985102045R is fitted in these vehicles: Smart Fortwo C453 (2014-2024). A comparison with the label of the removed unit shows whether it is the right unit.

The vehicles in detail:

• Smart Fortwo C453 (2014-2024)

Before removal, take these points into account. First have the fault memory read out, because only then is it clear whether the control unit is defective or whether a plug or cable is the cause. The comparison of the part number on the label merely confirms the unit.

For the same vehicles, we also repair control units with the part numbers A453 901 89 00, A4539001702, A4539017400.

How does the repair of the 985102045R work?

The process begins with reading out the fault memory, whose log is attached to the unit. Then you disconnect the battery and remove the control unit 985102045R; only after that do you create the repair order online and send the unit in.

For testing, repairing and function testing, Airbag24 usually allows 3–4 working days. Airbag24 examines the unit, repairs defective components, erases stored crash data and runs a 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 985102045R get to Airbag24?

You either send the 985102045R as a parcel, or you book a UPS collection for an extra charge. Airbag24 takes care of the return journey after the repair, also by UPS.

Put the printed repair order into the parcel, and pack the unit shock-proof.