B17A200 - Crash recording locked, crash data stored airbag control unit fault

What does error code B17A200 mean in the airbag control unit?

Error code B17A200 indicates on BYD vehicles that recording of the crash data in the airbag control unit is blocked. The affected part is the restraint system (SRS) control unit, which controls the deployment of the airbags, and it stores the fault in the fault memory and switches on the airbag warning light.

The code therefore describes a state in which stored crash data blocks recording. Crash data is created after an accident, and the message concerns precisely its recording in the unit.

The message therefore relates to the control unit itself and does not name any individual component.

How do you recognise error code B17A200?

You recognise error code B17A200 by an airbag warning light on the dashboard that stays permanently lit and indicates a fault in the restraint system. The code is held in the fault memory of the airbag control unit, cannot be permanently erased, and only becomes visible once a diagnostic tool reads out the fault memory.

Without a read-out, it remains unclear which code is stored. Only then can the cause be narrowed down, and all further steps build on this.

The read-out is therefore not an optional extra step, but the point at which the suspicion of this code is either confirmed or ruled out.

What causes error code B17A200?

The main possible cause of error code B17A200 is crash data from an accident that is stored in the airbag control unit and blocks recording. Faults in the control unit itself are also possible, because the message relates directly to this unit.

• voltage spikes caused by a weak battery or by jump-starting
• moisture or corrosion in the control unit
• solder joints and aged electronic components in the unit
• crash data from an accident

Connectors and wiring play no primary role with this code, because the message points to the control unit.

In which vehicles does error code B17A200 occur?

Error code B17A200 is known on BYD vehicles, namely on several models such as the Atto 2, Atto 3, Dolphin, Han, Seal and Tang. The list also includes the Dolphin Surf, Seal U and Sealion 7, as well as further models from the BYD range.

The list is not complete, and on other vehicles the meaning of the code may differ. Whether the code is present on your own vehicle is shown by reading it out with a diagnostic tool.

How is error code B17A200 resolved?

Error code B17A200 is resolved by first having the fault memory read out with a diagnostic tool so that the cause is established. If the cause lies in the control unit, disconnect the battery, remove the unit, create a repair order online and send the unit in for repair.

The control unit is only removed once the battery has been disconnected. Work on the airbag system should be left to qualified hands.

The check, the repair and the test 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.