Airbag control unit with part number 985108855R

What does the airbag control unit 985108855R do?

The airbag control unit 985108855R coordinates the restraint system (SRS) in Renault vehicles. It evaluates the crash sensors, determines the triggering of the airbags and seatbelt pretensioners in an accident within the shortest possible time, and monitors everything continuously. Faults appear on the airbag warning light; after an accident, the unit stores crash data and locks itself.

The decision to trigger brooks no delay, so diagnosis runs in the background. You do not need to operate anything for this.

In the workshop, therefore, the control unit, sensors and seatbelt pretensioners form one system, and a fault in one link can affect triggering.

Why does the control unit 985108855R fail?

Stored crash data is the most common cause of failure for 985108855R, even if no airbag has fired; a normal diagnostic tool cannot delete them. Other possible causes are aged electronic components, cold solder joints, moisture and corrosion on plug connections, and voltage spikes from a weak battery or a jump start.

The presence of crash data does not yet mean that the unit itself is damaged. Airbag24 deletes the crash data during the repair.

The other causes can only be identified with the fault memory, because you cannot tell from the outside whether moisture or a voltage spike has damaged a unit.

How can you tell that the 985108855R is defective?

A defect in the 985108855R shows up as an error message in the instrument cluster, accompanied by an airbag warning light that lights up permanently or intermittently. A diagnostic tool that cannot establish a connection to the control unit, or a fault memory that cannot be cleared, also indicate this. Airbags and seatbelt pretensioners may then not deploy in an emergency.

The light is not a minor matter; it reports a detected fault. If it lights up, have the vehicle checked promptly.

Only reading it out with a suitable diagnostic tool shows whether the fault memory contains further entries. The light itself does not name a cause.

Which vehicles is the 985108855R fitted in?

The airbag control unit 985108855R is fitted in these vehicles: Renault Mégane III (2008-2016). If your vehicle is included, the unit is in principle suitable.

The following vehicles are recorded with us:

• Renault Mégane III (2008-2016)

Compare the part number on the label of the removed unit with this page. This only confirms that it is the correct unit. Have the fault memory read beforehand; only it shows whether the control unit is defective or a connector or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 285581365R, 8200962388, 985105478R.

How does the repair of the 985108855R work?

Have the fault memory read out and the report attached before you disconnect the battery. Only then remove the control unit 985108855R and create a repair order online; then send it in, securely packed. At Airbag24, testing, repair and function test usually take 3–4 working days.

At Airbag24, the unit is examined on the test bench, defective components are replaced, stored crash data is deleted and a function test is run. Your own unit is then 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 985108855R get to Airbag24?

For shipping to Airbag24, you can use a parcel or a UPS collection booked for an extra charge. The repaired control unit 985108855R is then returned to you by UPS.

The printed repair order belongs in the parcel, and the unit needs shockproof packaging.