Airbag control unit with part number 1EA 959 655 AA

What does the airbag control unit 1EA 959 655 AA do?

The airbag control unit 1EA 959 655 AA is the central control unit of the restraint system (SRS) for Volkswagen. It evaluates the signals from the crash sensors and, in an accident, decides within milliseconds which airbags and seatbelt pretensioners are triggered.

During operation, the unit continuously monitors the entire system. If it detects a fault, it reports it via the airbag warning light in the instrument cluster.

After an accident, the control unit stores crash data and then locks itself.

Why does the control unit 1EA 959 655 AA fail?

The most common cause is crash data stored after an accident, even if no airbag has triggered. Other causes include aged electronic components, moisture and corrosion on plug connections, cold solder joints, and voltage spikes, for example from a weak battery or jump-starting.

Crash data cannot be erased with a normal diagnostic tool. Airbag24 therefore erases it.

On control units with a 1EA number, Airbag24 does not rectify internal defects caused by ageing, moisture or voltage spikes.

How can you tell that the 1EA 959 655 AA is defective?

The telltale sign is the airbag warning light in the instrument cluster staying on permanently or lighting up intermittently. A fault message in the instrument cluster, a diagnostic tool that cannot connect to the control unit, or a fault memory that cannot be cleared also point to a defect.

In an emergency, airbags and seatbelt pretensioners may then fail to deploy. The warning light is there to make such faults visible.

If it stays on permanently, reading out the fault memory is the right next step.

Which vehicles is the 1EA 959 655 AA fitted in?

The control unit 1EA 959 655 AA is fitted in these vehicles: Volkswagen Caddy SB (from 2020).

These vehicles are stored for this part number:

• Volkswagen Caddy SB (from 2020)

Compare the part number on the label of the removed unit with this page beforehand; this only ensures that you have the right unit in front of you. Also have the fault memory read out, because only the result shows whether the control unit is defective or whether a plug or a cable is the cause. If fault B2000 is shown there, not even the erasure of the crash data is possible on a control unit with a 1EA number; do not send the unit in then.

For the same vehicles, there are also control units with the part numbers 1EA 959 655 DD, 1EA 959 655 DM, 1EA 959 655 ED, 2H0959655B, 3AA919041A, 6Q0 909 605 AJ.

How does the erasure of the crash data on the control unit 1EA 959 655 AA work?

First have the fault memory read out and enclose the log. Then disconnect the battery and only then remove the control unit. Next, create a work order online and send in the well-packed unit; processing at Airbag24 usually takes 3–4 working days.

For control units with a 1EA number, Airbag24 offers only the erasure of stored crash data. Internal defects are not rectified in the process, and the unit itself is not checked.

After the crash data has been erased, your own unit comes back with all vehicle data and is ready for use as soon as it is refitted — no coding or programming is required.

If fault B2000 is stored in the fault memory, Airbag24 does not offer even the erasure of the crash data for control units with a 1EA number.

How does the control unit 1EA 959 655 AA get to Airbag24?

You send the unit as a parcel or book a UPS collection for an extra charge. After the crash data has been erased, Airbag24 returns it by UPS.

Put the printed work order into the parcel and pack the control unit so that it is protected against shocks.