Airbag control unit with part number P9452751

What does the airbag control unit P9452751 do?

The airbag control unit P9452751 is the central control unit of the restraint system (SRS) for Volvo. It evaluates the signals from the crash sensors, decides in an accident within milliseconds which airbags and seatbelt pretensioners to trigger, and monitors the system continuously.

In addition, the supplier number Bosch 0285001254 is affixed to the housing. The unit reports faults via the airbag warning light, and after an accident it stores crash data and locks itself.

Why does the control unit P9452751 fail?

With the P9452751, the most common cause is crash data stored in the memory after an accident, even if no airbag has been deployed. A normal diagnostic tool cannot delete this data. Other causes are aged electronics, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes.

These entries remain even when the vehicle drives again after the accident. The memory holds them until the unit is repaired.

Further influences also act on the unit:

• aged electronic components
• cold solder joints
• moisture and corrosion at plug connectors
• voltage spikes, for example from a weak battery or a jump start

How can you tell that the P9452751 is defective?

A defect in the P9452751 becomes visible through the airbag warning light, which lights up permanently or intermittently. Add to this a fault message and a missing diagnostic connection to the control unit. Then airbags and seatbelt pretensioners may fail to deploy in an emergency.

Specifically, you can recognise the defect by these signs:

• Airbag warning light on, permanently
• Airbag warning light on, intermittently
• Message in the instrument cluster
• Diagnostic tool cannot reach the control unit
• The fault memory cannot be cleared

With each of these signs, a prompt check is worthwhile.

Which vehicles is the P9452751 fitted in?

The P9452751 is fitted in these vehicles: Volvo XC70 P2 (2000-2004) and P2 Facelift (2004-2007); Volvo S80 TS (1998-2003) and TS Facelift (2003-2006); Volvo V70 S P26 (2000-2007). Whether the control unit itself is defective only shows when the fault memory is read out.

The models in detail:

• Volvo XC70 P2 (2000-2004)
• Volvo XC70 P2 Facelift (2004-2007)
• Volvo S80 TS (1998-2003)
• Volvo S80 TS Facelift (2003-2006)
• Volvo V70 S P26 (2000-2007)

Comparing the part number on the label with this page confirms that it is the right unit. Have the fault memory read out beforehand, because only the log shows whether the control unit is defective or a connector or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 0 285 001 456, 285001254, 285001655, 30695741, 30721921, 30782385.

How does the repair of the P9452751 work?

First have the fault memory read out and attach the log, then disconnect the battery and remove the control unit P9452751. Then create a repair order online and send the unit in well packed. Airbag24 checks and repairs it afterwards.

This sequence is mandatory for safety reasons, so removal takes place only after the battery has been disconnected.

At Airbag24 the unit is examined on the test bench, defective components are renewed, the crash data is deleted and a function test is carried out. Processing usually takes 3–4 working days. 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 P9452751 get to Airbag24?

You send the control unit P9452751 as a parcel or book a UPS collection for an extra charge. After processing, Airbag24 sends the repaired unit back to you by UPS.

Include the printed repair order in the parcel. Pack the unit shock-resistant before dispatch.