Airbag control unit with part number 7700414091

What does the airbag control unit 7700414091 do?

The airbag control unit 7700414091 is the central control unit of the restraint system (SRS) for Renault. It evaluates the signals from the crash sensors and decides in a crash, within milliseconds, which airbags and seatbelt pretensioners are triggered.

The unit monitors the entire system continuously. If it detects a fault, it reports it via the airbag warning light in the instrument cluster, even if the fault occurs only intermittently.

After an accident, the control unit stores crash data and locks itself. The next section explains what role this data plays in a failure.

Why does the control unit 7700414091 fail?

With the 7700414091, the most common cause is crash data stored after an accident, even if no airbag has fired. A standard diagnostic tool cannot erase this data. Other causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes, for example from a weak battery or a jump start.

The crash data is held in the memory of the control unit itself, independent of cables and plugs.

The other causes affect the electronics and their surroundings. Aging, moisture and corrosion attack components and connections, and voltage spikes additionally strain the unit.

How can you tell that the 7700414091 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently if the 7700414091 has a defect. In addition there may be an error message in the display, no connection to the diagnostic tool, and a fault memory that cannot be cleared.

It is important to take such signs seriously, because airbags and seatbelt pretensioners may not trigger in an emergency. This applies regardless of how the vehicle behaves in everyday use.

If the light stays on or comes back, have the system checked promptly.

Which vehicles is the 7700414091 fitted in?

The control unit 7700414091 is fitted in these vehicles: Renault Mégane I (1995-2003). You can check whether your vehicle is among them by make and model.

The vehicles in detail:

• Renault Mégane I (1995-2003)

Compare the part number on the label of the removed unit with this page, to make sure it is the right unit. Whether the control unit itself is defective or a plug or cable is the cause is shown only by reading out the fault memory. Have it read out before removal.

For the same vehicles, we also repair control units with the part numbers 600639500, 7700430059, 7700437477B, 8200117651, 8200117651A, 8200117652.

How does the repair of the 7700414091 work?

When removing the 7700414091, follow this sequence: first have the fault memory read out and enclose the log. Then disconnect the battery and only then remove the control unit. Finally, create a repair order online and send the well-packed unit in.

Airbag24 checks the unit on the test bench, replaces defective components, erases stored crash data and carries out a function test. Your own unit is returned to you afterwards.

Processing at Airbag24 usually takes 3–4 working days. This time covers only the checking, repairing and testing.

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 7700414091 get to Airbag24?

You send the 7700414091 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns the unit to you by UPS.

Put the printed repair order in the parcel and pack the unit shockproof.