Airbag control unit with part number 12778700

What does the airbag control unit 12778700 do?

The airbag control unit 12778700 controls the airbags and seatbelt pretensioners in the restraint system (SRS) on Saab. In an accident it decides on their triggering within milliseconds, based on the crash sensors, and monitors the system continuously. After an accident it stores crash data and locks itself.

It shows detected faults via the airbag warning light in the instrument cluster, so that you can see the fault.

Its task is limited to the restraint system; chassis and engine are not part of it.

Why does the control unit 12778700 fail?

Foremost are crash data stored after an accident, even without an airbag firing; a normal diagnostic tool does not erase them. In addition, aged components, cold solder joints, moisture and corrosion at plug contacts, and voltage spikes come into consideration.

Stored crash data remain as an entry, even if the vehicle continues to drive normally afterwards.

Ageing affects every electronic component. Solder joints can go cold over time, and moisture or corrosion at plug contacts disturbs the connection.

Voltage spikes, for example with a weak battery or when a jump start is connected, are a further possibility.

How can you tell that the 12778700 is defective?

The airbag warning light in the instrument cluster stays on permanently or lights up intermittently. A fault message accompanies it, the diagnostic tool cannot find the control unit, and a fault memory cannot be cleared. In that case the airbags and seatbelt pretensioners may possibly not fire in an emergency.

Intermittent lighting also counts as a finding and belongs to the check.

A diagnostic tool without a connection to the control unit indicates that something in the system is wrong. Then have a specialist workshop carry out the check.

Which vehicles is the 12778700 fitted in?

The control unit 12778700 is fitted in these vehicles: Saab 9-3 II YS3F (2002-2007) and II YS3F Facelift (2007-2011).

The list shows only the vehicles that are stored in our assignment.

• Saab 9-3 II YS3F (2002-2007)
• Saab 9-3 II YS3F Facelift (2007-2011)

Make the comparison of the part number on the label with this page before you send the unit in. It ensures that you have the right unit in front of you. Whether the control unit is defective, or plugs and cables are responsible for the fault, is shown by the fault memory. Have it read out beforehand.

For the same vehicles, we also repair control units with the part numbers 12762954, 12771236, 12771237, 12802256, 401662A6, A0417349.

How does the repair of the 12778700 work?

First have the fault memory read out and attach the log to the unit. Only then disconnect the battery and remove the control unit. Testing, repair and function test at Airbag24 usually take 3–4 working days.

Then create the repair order online and send in the well-packed unit.

Airbag24 checks the unit on the test bench, replaces defective components, erases stored crash data and runs a function test.

The sequence on the vehicle must be observed for safety reasons.

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 12778700 get to Airbag24?

You send the unit as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back by UPS.

Pack the unit shock-proof, and the printed repair order goes into the parcel as well.