Airbag control unit with part number A121B0060F

What does the airbag control unit A121B0060F do?

The airbag control unit A121B0060F controls the restraint system (SRS) in Lotus. It evaluates the sensor signals of an impact, decides within milliseconds on the triggering of airbags and seatbelt pretensioners, and keeps the system under observation during operation.

If the electronics detect a fault, they switch on the airbag warning light in the instrument cluster. This is how the driver learns that something in the restraint system needs to be checked.

After an accident, the control unit stores crash data and locks itself. The next section describes possible causes of failure.

Why does the control unit A121B0060F fail?

Stored crash data from an accident is the most common cause, even if no airbag has deployed. With this control unit, deleting this data is often not possible; for that reason, contact Airbag24 briefly before sending the unit in. Aged electronics, moisture at plugs, solder joints and voltage spikes are also involved.

A normal diagnostic tool does not remove this data from the memory; it therefore stays in the control unit. The other causes mainly concern the ageing of components and voltage spikes, for example from a weak battery when starting or from jump-starting.

How can you tell that the A121B0060F is defective?

A defect shows itself through the warning light, through error messages and through diagnosis. Then there is a risk that airbags and seatbelt pretensioners do not deploy in a real emergency.

The following signs stand out in detail:

• The airbag warning light in the instrument cluster stays on continuously or intermittently
• A message appears in the instrument cluster display
• The diagnostic tool does not communicate with the control unit
• The fault memory remains even after an attempt to clear it

Which vehicles is the A121B0060F fitted in?

The control unit A121B0060F is fitted in these vehicles: Lotus Elise Series 2 (2001-2011) and Series 3 (2011-2021); Lotus Exige Series 2 (2004-2011) and Series 3 (2012-2021); Lotus Europa S (2006-2010). The list is a guide, nothing more.

The assignment covers the following models:

• Lotus Elise Series 2 (2001-2011)
• Lotus Elise Series 3 (2011-2021)
• Lotus Exige Series 2 (2004-2011)
• Lotus Exige Series 3 (2012-2021)
• Lotus Europa S (2006-2010)

Comparing the part number on the label of the removed unit with this page only ensures that you have the correct unit in front of you. A fault memory read out in advance, on the other hand, shows whether the control unit is defective or whether a plug or cable is behind it.

For the same vehicles, we also repair control units with the part numbers A138M0195F.

How does the repair of the A121B0060F work?

First, have the fault memory read out; you enclose the log later. Then disconnect the battery and only at the end remove the control unit. Create the repair order online, then send the well-packed unit in. Airbag24 needs 3–4 working days in general for checking, repairing and testing.

At Airbag24, the unit is first checked on the test bench, then the defective parts are replaced and finally the function test is carried out. If you want the crash data deleted, contact Airbag24 briefly before sending the unit in.

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 A121B0060F get to Airbag24?

You hand in the unit as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns the unit by UPS.

Place the printed repair order in the parcel and pack the control unit shockproof.