AE00 - Airbag control unit N2/7 defective airbag control unit fault

What does error code AE00 mean in the airbag control unit?

Error code AE00 reports that the airbag control unit itself is faulty. On Mercedes-Benz it is called the restraint systems control unit. The unit has detected a fault in its own electronics and can therefore no longer reliably monitor and trigger the airbags and seatbelt pretensioners. The airbag warning light indicates this.

The airbag control unit evaluates the signals from the crash sensors and decides whether the airbags and seatbelt pretensioners deploy. If it detects a fault in itself, it stores error AE00 and switches on the airbag warning light. The problem is therefore not a single airbag or sensor, but the central evaluation unit of the restraint system.

How do you recognise error code AE00?

The airbag warning light in the instrument cluster stays on, and AE00 is stored in the fault memory. The entry can be read out with a diagnostic tool and returns after being cleared for as long as the control unit has the fault. Clearing it once does not change that.

The fault memory is read out with a diagnostic tool. An entry that cannot be cleared permanently suggests that the cause lies in the unit itself and is not a one-off glitch. The warning light alone, on the other hand, only shows that a fault is stored in the airbag system.

What causes error code AE00?

With error code AE00, the cause lies in the airbag control unit itself, not in the wiring. The electronics inside are affected, for example by stored crash data, aged components, damaged solder joints, moisture or voltage spikes.

• Crash data stored in the control unit after an accident
• aged electronic components inside the control unit
• cracks in solder joints on the circuit board
• moisture and corrosion that have reached the circuit board or connector
• voltage spikes, for example from a weak battery or a jump start

Which of these causes applies in a given case only becomes clear when the removed control unit is tested.

In which vehicles does error code AE00 occur?

Error code AE00 is known on Mercedes-Benz, namely on the E-Class W211, the C-Class W203 and the CLK-Class C209. On other vehicles the meaning may differ, and the list is not complete. Reading out your own vehicle will clarify this.

If you drive a different model, you may find the same entry in the fault memory with a different meaning. The readout on your own vehicle is therefore always decisive, not the code alone.

How is error code AE00 resolved?

Error code AE00 is resolved by testing and repairing the faulty airbag control unit. First the fault memory is read out with a diagnostic tool, then you send the removed control unit to Airbag24. There it is tested, repaired and checked on the test bench.

First have the fault memory read out at a specialist workshop so that the entry is confirmed. If the cause lies in the control unit, first disconnect the battery and then remove the control unit. Create a repair order online and send the unit to Airbag24. Checking, repairing and testing usually take 3–4 working days. Work on the airbag system belongs in expert hands.

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.