Airbag control unit with part number 77960-TEA-H820-M4

What does the airbag control unit 77960-TEA-H820-M4 do?

The airbag control unit 77960-TEA-H820-M4 coordinates the restraint system (SRS) in Honda vehicles. It reads the signals from the crash sensors, determines in an accident within milliseconds which airbags and seatbelt pretensioners deploy, and checks the entire system without interruption.

If the unit detects a fault, it reports it via the airbag warning light in the instrument cluster. In this way you learn that something is wrong in the restraint system.

After an accident, the control unit creates crash data and locks itself. The control of the seatbelt pretensioners and the evaluation of the sensors run in the background; you do not need to set anything for this.

Why does the control unit 77960-TEA-H820-M4 fail?

The most common cause is crash data from an earlier accident, even if no airbag was triggered. Aged components, cold solder joints, moisture or corrosion at plugs, and voltage spikes can also be the cause.

An ordinary diagnostic tool cannot remove the crash data. The unit therefore remains in the vehicle with this data until it is examined in a workshop.

Electronic causes within the control unit itself are also possible. Ageing of components and moisture at the connections are among the typical causes that are checked during an examination.

How can you tell that the 77960-TEA-H820-M4 is defective?

The airbag warning light in the instrument cluster stays on constantly or only intermittently. Accompanying this, a fault message appears, the diagnostic tool cannot reach the control unit, and the fault memory cannot be cleared. With such signs, the airbags and seatbelt pretensioners may possibly fail to deploy in an emergency.

The light is the visible part of the fault monitoring. That it only lights up at times is therefore no all-clear.

Only the readout of the fault memory shows whether the control unit itself is affected. Until then, you should not ignore the warning.

Which vehicles is the 77960-TEA-H820-M4 fitted in?

The control unit 77960-TEA-H820-M4 is fitted in these vehicles: Honda Civic 10th generation (2015-2022).

Here is the list of models that are recorded with this unit in our data:

• Honda Civic 10th generation (2015-2022)

Compare the part number on the label of the removed unit with this page. This only confirms that it is the right unit. In addition, have the fault memory read out before removal, because only this record shows whether the control unit itself is defective or a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 77960-SMG-G014-M1, 77960-TBA-A01, 77960-TBA-A02, 77960-TBA-A03, 77960-TBA-A04, 77960-TBA-A05.

How does the repair of the 77960-TEA-H820-M4 work?

At Airbag24, examining, repairing and testing usually take 3–4 working days. Beforehand, you have the fault memory read out, enclose the log and disconnect the battery before the control unit is removed. Afterwards, you create a repair order online and send the unit in well packed.

The order of the steps is for your safety, so keep to it strictly. Only after disconnecting the battery is the unit removed.

Airbag24 examines the unit on the test bench, replaces defective components, erases the stored crash data and carries out a function test. Afterwards, your own unit is returned 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-TEA-H820-M4 get to Airbag24?

You send the control unit 77960-TEA-H820-M4 to us as a parcel, or for an extra charge you book a UPS pickup. Airbag24 then returns the repaired unit to you by UPS.

The printed repair order goes into the parcel, and the control unit is packed shock-proof so that it is not damaged on the way.