Aston Martin Cygnet airbag control unit repair⁽¹⁾

What should I know about Aston Martin Cygnet airbag control units?

The airbag control unit in the Aston Martin Cygnet evaluates the crash sensors and determines which airbags and belt tensioners are triggered. If the system detects a fault, the airbag warning light comes on. Airbag24 repairs the control unit from your own vehicle that you send in.

The control unit monitors the entire restraint system of the vehicle. A fault can impair the function of the system, and the airbag warning light may stay on permanently. Typical causes include triggering after an accident with stored crash data, ageing of the electronics, overvoltage or battery problems, moisture on the connectors, and communication faults on the CAN bus.

After an accident, the control unit stores crash data and locks itself. The crash data must then be erased and the unit checked. Airbag systems are safety-critical. Work on them belongs in the hands of a specialist workshop and should not be carried out by yourself.

Which Aston Martin Cygnet generations are there?

Only one series is distinguished for the Aston Martin Cygnet. It was built from 2011 to 2013.

The Cygnet was a compact city car from Aston Martin. As there is only one series, the production period helps with a rough classification of your vehicle. However, the exact allocation of the control unit is made using the part number, not the model year alone.

The series at a glance:

• Cygnet (2011–2013) – the only series of this model.

How do I identify my Aston Martin Cygnet airbag control unit?

The part number on the label of the control unit determines the exact version. In addition, check the model year and equipment of your vehicle, as both help with the allocation.

The label is often located directly on the housing of the control unit. The following part numbers are known for this model. The list does not claim to be complete:

• Part number 89170-74030
• Part number 89170-74040
• Part number 89170-74130
• Part number 89170-74140

The supplier of these control units is Denso. Before sending in the unit, note the part number, model year and vehicle identification number (VIN). Fault codes can give first indications, for example 0131 for an internal component fault, 013B for crash events stored in the crash memory, or 0005 for battery voltage that is too low. However, a single fault code does not prove a defect in the control unit. A specialist workshop determines the cause.

Which airbag equipment does the Aston Martin Cygnet have?

The Aston Martin Cygnet is fitted as standard with an airbag system that includes curtain airbags and a knee airbag, among others. The exact number and arrangement of the airbags depend on the specification and can be found in the vehicle handbook.

The curtain airbags protect the head area in the event of side impacts. The knee airbag supplements the protection of the driver's knees. Further airbags and belt tensioners are coordinated by the control unit, provided they are fitted in the vehicle.

The control unit coordinates the deployment of all airbags and belt tensioners. If it fails, the entire restraint system may be affected. If the airbag warning light is on, the system should be checked promptly by a specialist workshop.

This is how to proceed: have the fault memory read out at a specialist workshop. Before any work on the airbag system, the battery must be disconnected, and removing the control unit is also a task for the specialist workshop. Then create a repair order online and send the removed control unit, well packed, by parcel to Airbag24. Processing usually takes 3–4 working days (checking, repairing, testing).

The repaired control unit returns with all vehicle data and is ready for use immediately after reinstallation — no coding or programming is necessary.