Airbag control unit with part number 77960-TEA-Z420-M4

What does the airbag control unit 77960-TEA-Z420-M4 do?

The airbag control unit 77960-TEA-Z420-M4 is the central control unit of the SRS restraint system of Honda. In an accident it decides which airbags and seatbelt pretensioners are triggered, and it makes this decision within milliseconds.

To do so it reads the signals from the crash sensors. At the same time it monitors the entire system, and faults appear via the airbag warning light in the instrument cluster.

After an accident the control unit stores crash data and locks itself. The lock is only lifted by the repair.

Why does the control unit 77960-TEA-Z420-M4 fail?

Stored crash data is the most common cause, even if no airbag was triggered in the accident. A usual diagnostic tool cannot erase this data.

Airbag24 erases the crash data during the repair. Other causes are ageing electronic components, cold solder joints, and moisture and corrosion at plug connections. Voltage spikes, for example from a weak battery or a jump start, are added to these.

How can you tell that the 77960-TEA-Z420-M4 is defective?

The airbag warning light in the instrument cluster comes on permanently or intermittently as soon as there is a defect on the 77960-TEA-Z420-M4. Possibly a fault message, a diagnostic tool without a connection to the control unit and a fault memory that cannot be cleared come with it.

As long as the system is disturbed, airbags and seatbelt pretensioners may fail to trigger in a crash. Please have the finding checked promptly.

Which vehicles is the 77960-TEA-Z420-M4 fitted in?

The control unit 77960-TEA-Z420-M4 is fitted in these vehicles: Honda Civic 10th generation (2015-2022).

The overview below shows the vehicles that are recorded for this unit in our data.

• Honda Civic 10th generation (2015-2022)

Have the fault memory read out in advance, so that you know whether the control unit itself is defective or whether a plug or a cable is involved. Then compare the part number on the label of the removed unit.

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-Z420-M4 work?

Before removal you have the fault memory read out, attach the record, disconnect the battery and remove the control unit. After that you create a repair order online. Processing at Airbag24 usually takes 3–4 working days.

You then send the well-packed unit in. Airbag24 checks it on the test bench, repairs defective components and erases the crash data.

After that a functional test follows, and then 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-Z420-M4 get to Airbag24?

You send the control unit 77960-TEA-Z420-M4 as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 returns it to you by UPS.

Place the printed repair order in the parcel, and the unit should be packed shock-resistant.