Airbag control unit with part number 4E0 959 655 E

What does the airbag control unit 4E0 959 655 E do?

The airbag control unit 4E0 959 655 E is the central control unit of the SRS restraint system of Audi. Through the crash sensors it records accelerations, decides within milliseconds in a crash whether to trigger, and monitors the system continuously.

The unit reports faults via the airbag warning light in the instrument cluster.

In addition, it stores crash data after an accident and locks itself.

Why does the control unit 4E0 959 655 E fail?

The most common cause in the 4E0 959 655 E is crash data stored after an accident, even without a triggered airbag. Other causes are ageing components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

An ordinary diagnostic tool cannot reach this crash data; Airbag24 erases it during the repair. Further causes at a glance:

• Electronic components that age over time
• Cold solder joints on the circuit board
• Moisture and corrosion at plugs
• Voltage spikes, for example from a weak battery or a jump start

How can you tell that the 4E0 959 655 E is defective?

You can recognise a defect in the 4E0 959 655 E by the airbag warning light, error messages in the instrument cluster, a missing connection to the diagnostic tool or a fault memory that cannot be cleared.

Pay attention to these signs:

• Warning light on permanently or intermittently
• Error message in the instrument cluster
• Diagnostic tool cannot establish a connection to the control unit
• Fault memory cannot be cleared

Airbags and seatbelt pretensioners may then fail to trigger in an emergency. The warning light reports the fault, so a check is advisable.

Which vehicles is the 4E0 959 655 E fitted in?

The 4E0 959 655 E is fitted in these vehicles: Audi S8 D3 (2006-2008) and D3 Facelift (2008-2010); Audi A8 D3 4E (2002-2005) and D3 4E Facelift (2005-2010).

The following list shows the vehicles stored for this part number.

• Audi S8 D3 (2006-2008)
• Audi S8 D3 Facelift (2008-2010)
• Audi A8 D3 4E (2002-2005)
• Audi A8 D3 4E Facelift (2005-2010)

Comparing the part number on the label of the removed unit with this page only confirms that it is the right unit.

Have the fault memory read out beforehand, because only this result shows whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 0285001672, 0285001705, 285001512, 285001705, 4E0 959 655 H, 4E0910655.

How does the repair of the 4E0 959 655 E work?

You read out the fault memory first and enclose the printout. Then you disconnect the battery and only then remove the 4E0 959 655 E. Next, you create a repair order online. Processing at Airbag24 usually takes 3–4 working days.

The unit is checked on the test bench, defective components are replaced, the crash data is erased and the function is tested. Afterwards, your own unit goes back to you.

The 3–4 working days refer only to this work at Airbag24 and have nothing to do with your steps or the shipping.

Our repairs come with 2 years' statutory liability for defects. 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.

How does the control unit 4E0 959 655 E get to Airbag24?

You send the 4E0 959 655 E as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back by UPS.

The printed repair order goes into the parcel, and the unit must be packed shockproof.