Airbag control unit with part number 77960-3W0-A820-M2

What does the airbag control unit 77960-3W0-A820-M2 do?

As the SRS control unit for Honda, the airbag control unit 77960-3W0-A820-M2 ensures that the correct airbags and seatbelt pretensioners fire in a crash. To do this it reads the crash sensors, makes the decision within milliseconds and monitors the system continuously. It reports detected faults via the airbag warning light.

The unit works in the background during every journey. It constantly compares the measured values with the expected values, so conspicuous deviations are quickly noticed.

After an accident it records crash data and then locks itself.

Why does the control unit 77960-3W0-A820-M2 fail?

Stored crash data is the most common cause, even if no airbag fired in the accident. A standard diagnostic tool cannot reach this data; it stays in the memory.

Aged electronic components, cold solder joints, and moisture and corrosion at plug connections may also trigger the fault. Voltage spikes, for example from a weak battery or a jump start, are a conceivable cause too.

At Airbag24 the crash data is erased during repair; the other causes are considered during the inspection.

How can you tell that the 77960-3W0-A820-M2 is defective?

A defect at the 77960-3W0-A820-M2 can be recognised by several features that become visible in the vehicle. The main ones are:

• The airbag warning light in the instrument cluster lights up permanently.
• The airbag warning light appears only intermittently.
• An error message is displayed in the instrument cluster.
• The diagnostic tool gets no connection to the control unit.
• The fault memory remains, even if you clear it.

In that case the airbags and seatbelt pretensioners may not trigger in an emergency.

Which vehicles is the 77960-3W0-A820-M2 fitted in?

The 77960-3W0-A820-M2 is fitted in these vehicles: Honda HR-V 3rd generation (from 2021).

The overview here lists the vehicles assigned to this part number.

• Honda HR-V 3rd generation (from 2021)

Check the part number on the label of the removed unit against this page; that way you know you have the correct unit. Have the fault memory read out before removal as well, because only the log shows whether the control unit is defective or a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 77960-T7S-X410-M1, 77960-T7S-X410-M2.

How does the repair of the 77960-3W0-A820-M2 work?

When repairing the 77960-3W0-A820-M2, first have the fault memory read out and attach the log, then disconnect the battery and remove the control unit. Then create the repair order online and pack the unit well. Processing at Airbag24 usually takes 3–4 working days, after which your own unit goes back to you.

During this time Airbag24 removes the stored crash data, replaces defective components and carries out a function test.

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 77960-3W0-A820-M2 get to Airbag24?

You send the 77960-3W0-A820-M2 to us as a parcel, or you book a UPS collection for an extra charge. The return after the repair is made by UPS.

Put the printed repair order into the parcel and pack the unit shockproof.