Airbag control unit with part number P30724427

What does the airbag control unit P30724427 do?

The airbag control unit P30724427 forms the central control unit of the SRS system of Volvo. It processes the messages from the crash sensors and decides within milliseconds which airbags and seatbelt pretensioners are triggered in an accident. After a crash, it stores crash data and locks itself.

The unit works continuously and monitors the entire chain from the sensor to the firing elements. It records irregularities and displays them via the airbag warning light.

As a result, the driver learns of a problem long before an emergency occurs. This is precisely the purpose of continuous monitoring.

Why does the control unit P30724427 fail?

The most common cause with P30724427: crash data stored after an accident, even if no airbag has deployed. A normal diagnostic tool cannot erase them. Other causes are aged components, cold solder joints, moisture at plug connections and voltage spikes.

The crash data remain in the unit until Airbag24 removes them during the repair.

These include:

• aged electronic components
• cold solder joints
• moisture and corrosion at the plug connections
• voltage spikes, for example from a weak battery or jump-starting

Which of these applies only becomes clear during the test on the test bench.

How can you tell that the P30724427 is defective?

A defect on the P30724427 shows up as the airbag warning light in the instrument cluster, which stays on permanently or intermittently, and as a fault message in the instrument cluster. Add to this a diagnostic tool without connection to the control unit and a fault memory that cannot be cleared.

In an emergency, airbags and seatbelt pretensioners may then fail to deploy, so such signs call for a prompt check. The warning light is the clearest signal the vehicle gives you.

How pronounced the symptoms are depends on the individual case.

Which vehicles is the P30724427 fitted in?

The control unit P30724427 is fitted in these vehicles: Volvo S40 M (2004-2007) and M Facelift (2007-2012).

For the assignment, model year, engine variant and equipment are decisive, not the make alone. The same make therefore does not automatically mean the same unit.

Here are the vehicles in detail:

• Volvo S40 M (2004-2007)
• Volvo S40 M Facelift (2007-2012)

Comparing the part number on the label of the removed unit with this page only shows that it is the right unit. Whether the control unit is defective or a plug or cable is the cause is shown only by the fault memory. So have it read out beforehand.

For the same vehicles, we also repair control units with the part numbers 30773401, 31334738, P30724652, P30773354, P30773401, P31295109.

How does the repair of the P30724427 work?

The process starts with reading out the fault memory. Then you disconnect the battery and only then remove the control unit P30724427. You enclose the protocol with the unit, create a repair order online and send it in. At Airbag24, checking, repairing and testing usually take 3–4 working days.

Airbag24 tests the unit on the test bench, replaces defective components, erases the stored crash data and carries out a function test. Afterwards your own unit goes back to you.

The sequence is fixed 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 P30724427 get to Airbag24?

The unit is sent to Airbag24 as a parcel, or you book a UPS collection for an extra charge. The return after the repair is likewise by UPS.

Inside the parcel is the printed repair order, and the unit is additionally packed in shock-proof wrapping.