Airbag control unit with part number P31350547

What does the airbag control unit P31350547 do?

The airbag control unit P31350547 is the central control unit of the restraint system (SRS) for Volvo. It evaluates the sensors, determines in a crash which airbags and seatbelt pretensioners trigger, and continuously monitors the condition of the system.

The calculation takes place within milliseconds. To this end the unit constantly runs its own self-tests and detects deviations early.

If the system detects a fault, the airbag warning light in the instrument cluster lights up. After an accident the control unit stores crash data and locks itself. The lock is only lifted by the repair.

Why does the control unit P31350547 fail?

Stored crash data from an accident are the most common cause, and this applies even when no airbag triggered; a common diagnostic tool does not remove them. In addition, aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes from a weak battery or jump starting come into question.

Crash data remain in the control unit until they are deleted during the repair. Whether an airbag triggered is irrelevant for the recording.

Aged components, cold solder joints and corrosion develop gradually. Voltage spikes when starting with external power, by contrast, act suddenly.

How can you tell that the P31350547 is defective?

You can recognise a defect on the P31350547 by an airbag warning light that stays on permanently or intermittently, an error message in the instrument cluster, a diagnostic tool without connection to the control unit, or a fault memory that cannot be cleared.

As long as the fault exists, airbags and seatbelt pretensioners may possibly not trigger in an emergency. An indication of this kind should therefore be checked immediately.

A missing connection of the diagnostic tool is also a sign that something is wrong with the control unit or its connection.

Which vehicles is the P31350547 fitted in?

The control unit P31350547 is fitted in these vehicles: Volvo V40 Serie 2 (2012-2016).

The assigned vehicles follow below in list form.

• Volvo V40 Serie 2 (2012-2016)

A comparison of the part number on the label of the removed unit with this page only confirms the identity of the unit. Have the fault memory read out beforehand, because only this log 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 285001147, 30611294, 30612702D, P31406938, P31429510.

How does the repair of the P31350547 work?

First have the fault memory read out and attach the log, then disconnect the battery. Only afterwards do you remove the control unit. Processing at Airbag24 usually takes 3–4 working days.

Then create the repair order online and pack the unit well before you send it in.

Airbag24 checks the unit on the test bench, repairs defective components, deletes the crash data and carries out a function test. Afterwards your own unit is 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 P31350547 get to Airbag24?

You send the control unit P31350547 to Airbag24 by parcel or book a UPS collection for an extra charge. The return shipment after the repair is made by UPS.

Shock-proof packaging and the enclosed printed repair order belong in the parcel.