Airbag control unit with part number 77960-SZT-H820-M2

What does the airbag control unit 77960-SZT-H820-M2 do?

The airbag control unit 77960-SZT-H820-M2 coordinates the restraint system (SRS) at Honda. It reads the crash sensors and determines in an accident, within milliseconds, which airbags and seatbelt pretensioners are triggered.

During operation it checks the system continuously for faults. If a fault is detected, the message appears via the airbag warning light.

After an accident, the unit records crash data and locks itself.

Why does the control unit 77960-SZT-H820-M2 fail?

The most common cause is crash data from an accident, which remains stored even when no airbag has fired and which cannot be erased with an ordinary diagnostic tool. Ageing electronics, cold solder joints, moisture at plug connections with corrosion, and voltage spikes may also be the cause.

The crash data stays in the memory even when nothing can be seen on the airbags from outside. Airbag24 erases it during the repair.

The remaining causes concern components and connections. Electronics can age, solder joints can stay cold, and moisture promotes corrosion.

Voltage spikes, for example from a weak battery or jump-starting, also harm the electronics.

How can you tell that the 77960-SZT-H820-M2 is defective?

A defect in the 77960-SZT-H820-M2 shows itself through the airbag warning light, which lights up permanently or at times, through an error message in the instrument cluster, through a diagnostic tool with no connection to the control unit, and through a fault memory that cannot be erased. In a real emergency, airbags and seatbelt pretensioners may then fail to deploy.

The signs at a glance:

• Airbag warning light in the instrument cluster
• Error message in the instrument cluster
• Diagnostic tool cannot find the control unit
• Fault memory cannot be erased

The light reports the fault on its own. Do not ignore it, or the cause will remain open.

Which vehicles is the 77960-SZT-H820-M2 fitted in?

The 77960-SZT-H820-M2 is installed in these vehicles: Honda CR-Z ZF1 (2010-2016).

This list shows the vehicles stored for this part number.

• Honda CR-Z ZF1 (2010-2016)

First compare the part number on the label of the removed unit with this page; that only confirms you have the right unit. Also have the fault memory read out beforehand, because only that 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 77960-SZT-A011, 77960-SZT-A011-M2.

How does the repair of the 77960-SZT-H820-M2 work?

For the 77960-SZT-H820-M2, first have the fault memory read out and enclose the log. Only then disconnect the battery and remove the control unit. Next, create a repair order online and send the unit off well packed. Airbag24 needs 3–4 working days as a rule for testing, repairing and checking.

The sequence is fixed for safety reasons. At Airbag24, the unit is checked on the test bench, defective components are replaced, the stored crash data is deleted, and a functional test follows. Your own, repaired unit comes back to you.

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 77960-SZT-H820-M2 get to Airbag24?

The 77960-SZT-H820-M2 reaches Airbag24 as a parcel if you send it yourself, or by UPS collection, which is booked for an additional charge. After the repair, Airbag24 sends it back via UPS.

Pack the unit shock-proof and enclose the printed repair order.