Airbag control unit with part number 7700414090

What does the airbag control unit 7700414090 do?

The airbag control unit 7700414090 coordinates the restraint system (SRS) for Renault as its control unit. It reads the crash sensors, makes the decision in a crash within milliseconds on whether airbags and seatbelt pretensioners are triggered, and passes on faults via the airbag warning light.

The electronics must be ready for operation at all times, because a crash leaves no time for detours. The system is also monitored continuously, not only in the event of an accident.

After an accident, the unit stores crash data and locks itself. This is part of how the unit behaves after an accident.

Why does the control unit 7700414090 fail?

Stored crash data are the most common cause when the control unit 7700414090 fails, even if no airbag has deployed. A normal diagnostic tool cannot erase them. Other causes are aged components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

The crash data remain in the memory after the event. A common reading tool cannot remove them, and the fault memory stays in place.

The other causes lie in the electronics or at their connections. Components age, solder joints can turn cold, and moisture attacks plug connections. Voltage spikes, for example from a weak battery or a jump start, also strain the circuit.

How can you tell that the 7700414090 is defective?

The airbag warning light in the instrument cluster lights up on a defective 7700414090 permanently or intermittently. An error message also appears in the instrument cluster, and the diagnostic tool finds no connection to the control unit.

A fault memory that cannot be cleared is another sign. Signs like these mean that airbags and seatbelt pretensioners may not deploy in an emergency.

Have these signs checked promptly. This includes reading out the fault memory, which determines the next steps.

Which vehicles is the 7700414090 fitted in?

The control unit 7700414090 is fitted in this vehicle: Renault Mégane I (1995-2003).

The vehicles known to us for this unit:

• Renault Mégane I (1995-2003)

On the one hand, compare the part number on the label of the removed unit with this page; this only ensures that it is the right unit. On the other hand, have the fault memory read out beforehand. Only this result shows whether the control unit itself is defective or a plug or cable is the cause.

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 7700414090 work?

First read out the fault memory and enclose the log. Then disconnect the battery and only then remove the control unit 7700414090; next create a repair order online and send the unit in well packed. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 checks the unit on the test bench, repairs defective components, erases stored crash data and carries out a function test. The 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 7700414090 get to Airbag24?

You can send the control unit 7700414090 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns it by UPS.

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