Audi S5 F57 Convertible airbag control unit repair

What is an Audi S5 F57 Convertible airbag control unit?

The airbag control unit is the central control unit of the restraint system (SRS) in the Audi S5 F57 Convertible. It evaluates the signals from the crash sensors and, in an accident, decides within milliseconds which airbags and seatbelt pretensioners deploy. After an accident it stores crash data and locks itself.

How can you tell that this control unit is involved? Usually from the airbag warning light in the instrument cluster and from entries in the fault memory. The control unit continuously monitors the entire restraint system and reports every detected fault via this light.

The control unit is installed in the Audi S5 F57 Convertible (2017 to 2024). As long as everything is in order, it works unobtrusively in the background and checks the connected sensors and squib circuits at every start.

Why is the Audi S5 F57 Convertible airbag control unit defective?

The most common cause is crash data stored after an accident, even if no airbag deployed. Other causes are aged electronic components, cold solder joints, moisture and corrosion on connectors, and voltage spikes. On the Audi S5 F57 Convertible, a defect usually shows up as the warning light.

Stored crash data cannot be cleared with an ordinary diagnostic tool. The control unit then stays in a fault state, even though the bodywork may be undamaged.

Voltage spikes occur, for example, with a weak battery or when jump-starting. Moisture and corrosion on the connectors disturb signal transmission, and over the years electronic components age or solder joints turn cold.

Typical signs: the airbag warning light stays on permanently, the fault memory cannot be cleared, or the diagnostic tool cannot connect to the control unit.

Common error codes for Audi S5 F57 Convertible airbag control unit repair

The error codes on the Audi S5 F57 Convertible mainly point to internal control unit faults, problems with the power supply and faults in the airbag squib circuits. They are read out of the fault memory with a diagnostic tool.

These error codes occur frequently on this vehicle series:

• 65535 → Control unit reports internal fault
• 00532 → Supply voltage too low, intermittent
• 00588 → Driver airbag squib circuit, resistance fault
• 00590 → Passenger airbag squib circuit, fault
• 01217 → Driver-side side airbag squib circuit, resistance fault
• 01218 → Passenger-side side airbag squib circuit, resistance fault

A code alone does not reliably show that the control unit is defective. Connectors, wiring or an airbag module can also be the cause. Only the inspection clarifies where the fault actually lies.

What part numbers are available for the Audi S5 F57 Convertible airbag control unit repair?

The part number is printed on the label of the control unit and determines the exact version. Within the Audi S5 F57 Convertible model series there are different numbers depending on equipment and year of manufacture.

We know of these part numbers, but the list is not necessarily complete:

• 8W0959655M
• 8W0959655P
• 8W7959655

Compare the number on your unit with this list. This only confirms that it is the right unit. Whether it is defective is shown only by reading out the fault memory or by the inspection.

Here is how to proceed with the repair: have the fault memory read out, disconnect the battery and remove the control unit. Create a repair order online and send in the unit. Processing at Airbag24, with inspection, repair and testing, usually takes 3–4 working days.

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.