Airbag control unit with part number P30724652

What does the airbag control unit P30724652 do?

The airbag control unit P30724652 is the central control unit of the restraint system (SRS) for Volvo. It evaluates the signals from the crash sensors, decides within a split second in an accident whether airbags and seatbelt pretensioners are triggered, and monitors the system continuously. Detected faults are reported via the airbag warning light.

During driving, the unit works unnoticed in the background. It constantly checks whether all connected components deliver plausible values and records any deviations in the fault memory.

After an accident, the control unit stores crash data and locks itself. This lock remains in place until a repair removes it.

Why does the control unit P30724652 fail?

The most common cause is crash data stored after an accident, even if no airbag was triggered; a standard diagnostic tool cannot erase it. 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 jump-starting.

The crash data cause a fault to stay reported, even though the electronics themselves may be working perfectly.

The other causes act over a longer period: moisture reaches the contacts, corrosion increases resistance, and ageing components eventually deliver values outside the target range.

How can you tell that the P30724652 is defective?

A defect shows up as an airbag warning light in the instrument cluster that stays on permanently or intermittently, as a fault message in the instrument cluster, and as a diagnostic tool that cannot establish a connection with the control unit. In addition, the fault memory cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

• Airbag warning light on permanently or intermittently
• Fault message in the instrument cluster
• No connection between diagnostic tool and control unit
• Fault memory cannot be cleared

If you notice any of these signs, have the system checked promptly. The warning light is the vehicle's own signal, and it must not be ignored.

Which vehicles is the P30724652 fitted in?

The airbag control unit P30724652 is fitted in these vehicles: Volvo S40 M (2004-2007) and M Facelift (2007-2012).

The vehicles in which this unit is found are listed here:

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

Before removal, compare the part number on the unit's label with this page. This only confirms that you have the correct unit in front of you. Also have the fault memory read out, because only this log shows whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 30773401, 31334738, P30724427, P30773354, P30773401, P31295109.

How does the repair of the P30724652 work?

First have the fault memory read out and enclose the log, then disconnect the battery and remove the control unit. Next, create a repair order online and send in the well-packed unit. 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. 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 P30724652 get to Airbag24?

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

Place the printed repair order in the parcel and pack the control unit so that it is protected against knocks.