Alpine A110 airbag control unit repair

What is an Alpine A110 airbag control unit?

The airbag control unit is the central control unit of the restraint system (SRS) in the Alpine A110. It monitors the system continuously, evaluates the signals from the crash sensors in an accident and decides within milliseconds which airbags and seatbelt pretensioners to deploy. After an accident it stores crash data and locks itself.

In everyday driving, the control unit only draws attention when something is wrong: when the ignition is switched on it runs a self-test, and the airbag warning light goes out again after a short time. It is installed in the Alpine A110 (since 2017). The control unit is made by Continental.

If the control unit detects a fault in sensors, squib circuits or wiring during the self-test or later in operation, it reports it via the warning light in the instrument cluster. If the light stays on, the restraint system is no longer reliably ready for use.

Why is the Alpine A110 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.

Crash data cannot be erased with an ordinary diagnostic tool. The control unit is then locked, and the warning light does not go out, even if the vehicle looks fine from the outside.

Electronic components age over the years, and solder joints can develop cracks and become cold. Moisture and corrosion on connectors disrupt signal transmission. Voltage spikes, for example from a weak battery or jump-starting, put additional strain on the electronics.

Typical signs are a permanently lit airbag warning light, a fault memory that cannot be cleared, or a diagnostic tool that cannot connect to the control unit.

Common error codes for Alpine A110 airbag control unit repair

The error codes on the Alpine A110 usually indicate that communication with the control unit is disrupted. The code then points to a failed connection, not to a single airbag.

This code occurs on this vehicle:

• U0151 → Communication with the airbag control unit lost

Error codes are read out with a diagnostic tool. 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 will clarify it.

What part numbers are available for the Alpine A110 airbag control unit repair?

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

The following list gives known part numbers for the Alpine A110, without any claim to completeness:

• 985105895R (Continental)

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

First have the fault memory read out, then disconnect the battery and remove the control unit. Then 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.