BYD Atto 2 1st generation airbag control unit repair

What is a BYD Atto 2 1st generation airbag control unit?

In the BYD Atto 2 1st generation, the airbag control unit is the central control unit of the restraint system (SRS). It evaluates the signals from the crash sensors, triggers the appropriate airbags and seatbelt pretensioners within milliseconds in an accident, and reports faults via the airbag warning light.

The control unit is installed in the BYD Atto 2 1st generation (since 2025). While driving, it continuously monitors the entire system, that is, sensors, squib circuits and power supply.

If an accident occurs, the control unit stores crash data and locks itself.

A sign that your control unit is affected is usually an illuminated airbag warning light or a restraint system entry in the fault memory.

Why is the BYD Atto 2 1st generation airbag control unit defective?

In the BYD Atto 2 1st generation, the most common cause is crash data that remains in the control unit after an accident, even if no airbag was triggered. Other possible causes are ageing of the electronic components, cold solder joints, corrosion and moisture at the connectors, and voltage spikes, for example from jump-starting or a weak battery.

A normal diagnostic tool cannot remove this stored crash data. The fault therefore remains.

A fault is indicated when the airbag warning light stays on constantly, the fault memory cannot be reset, or the diagnostic tool cannot make contact with the control unit.

A failure does not require an accident; ageing or moisture can also cause it. And a defective control unit does not mean that an airbag was triggered. Only the inspection determines the exact cause.

Common error codes for BYD Atto 2 1st generation airbag control unit repair

The error codes in the BYD Atto 2 1st generation show which part of the restraint system is affected: communication in the vehicle, the control unit itself, the power supply, a squib circuit or the stored crash data.

A code can point to different parts of the system. Sometimes it refers to the data line to other control units, sometimes to the power supply, sometimes to a connected airbag or to the control unit itself. The following codes are known for this vehicle:

• B16AE00 → General fault in the SRS control unit
• B17A000 → Internal control unit fault
• B17A200 → Crash data recording locked
• B17A600 → Frontal impact detected by the control unit
• B17A800 → CAN bus communication interrupted
• B1694 → Supply voltage too low
• B1695 → Supply voltage too high
• B1600 → Driver front airbag not connected

To diagnose the problem, you read out the fault memory with a diagnostic tool. Because connectors, wiring or an airbag module can also trigger a message, a single entry does not yet prove that the control unit is defective. Only the inspection gives certainty.

Write down the codes you have read out or save the log, and enclose it with the device you send in. This helps to narrow down the cause more quickly.

What part numbers are available for the BYD Atto 2 1st generation airbag control unit repair?

You will find the part number on the label of the control unit in the BYD Atto 2 1st generation. It determines the exact version, because within a model range there are different numbers depending on equipment and year of manufacture.

Copy the number from your device into the repair order. This allows us to assign the matching version. Whether the device is actually defective only becomes clear from reading out the fault memory or from the inspection.

The route to repair: have the fault memory read out, disconnect the battery and remove the control unit. Then create a repair order online and send in the device. At Airbag24, inspecting, repairing and testing usually take 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.