93D6 - Internal control unit fault, control unit not locked airbag control unit fault

What does error code 93D6 mean in the airbag control unit?

In BMW vehicles, the error code 93D6 reports an internal control unit fault, in which the control unit is not locked, meaning the fault lies in the control unit itself. The airbag control unit stores the fault as soon as the internal fault is detected and switches on the airbag warning light.

The airbag control unit itself is affected, meaning the central electronics of the restraint system.

In the event of a crash, the control unit deploys airbags and seatbelt pretensioners, which is why its own functionality is crucial.

How do you recognise error code 93D6?

Error code 93D6 is recognised by an airbag warning light that stays on permanently and does not go out by itself. The code is stored in the fault memory of the airbag control unit, cannot be permanently erased and is read out with a diagnostic tool, so the internal fault becomes visible.

The airbag warning light shows that an internal fault has been detected in the control unit, and it remains lit until the repair.

Clearing the code is only possible temporarily while the fault persists, because it is stored again afterwards.

What causes error code 93D6?

Error code 93D6 is triggered by faults that arise inside the control unit itself, for example through ageing, moisture or crash data after an accident. Which cause applies only becomes clear through diagnosis and testing of the control unit, so the code alone is not enough to determine the exact cause.

• Crash data from an accident is stored in the control unit
• Ageing electronic components in the control unit
• Solder joints in the control unit are damaged
• Moisture or corrosion has attacked the electronics
• Voltage spikes from a weak battery or jump-starting

An accident in the vehicle's history makes a link with the stored crash data likely. Testing the control unit shows which of the listed causes is actually present.

In which vehicles does error code 93D6 occur?

The error code 93D6 is known in BMW vehicles, for example on the X3, X4, X5, X6, XM, i5 and iX3 models, including M variants of the X3, X4, X5 and X6. The selection covers vehicles from various model series known for the BMW make.

The meaning may differ for other vehicles, and the list is not complete. Please check whether your model appears in this selection before taking further steps. If in doubt, reading out the fault memory will confirm whether the code is present on your vehicle.

How is error code 93D6 resolved?

Error code 93D6 is resolved by first having the fault memory read out with a diagnostic tool and narrowing down the cause. Because the fault lies in the control unit itself, the unit is sent to Airbag24 for repair after removal and checked there.

Working on the airbag system should be left to qualified professionals. This applies to removing the control unit as well as to all further steps.

Disconnect the battery first and then remove the control unit. Then create a repair order online and send the unit to Airbag24. Checking, 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.