Airbag control unit with part number 77960-TEA-Y420-M4

What does the airbag control unit 77960-TEA-Y420-M4 do?

The airbag control unit 77960-TEA-Y420-M4 forms the central switching point of the restraint system (SRS) in the Honda. It processes the reports from the crash sensors and triggers the appropriate airbags and seatbelt pretensioners in an accident. In addition, it monitors the system constantly and displays faults via the airbag warning light.

After an accident the control unit stores crash data and locks itself. The control remains active in the background and continues to evaluate signals.

Sensors and control unit are connected via the vehicle's wiring harness, which is why plug connections also play a role.

Why does the control unit 77960-TEA-Y420-M4 fail?

The most common cause with the 77960-TEA-Y420-M4 is stored crash data, which can arise even after an accident without an airbag triggering. A normal diagnostic tool cannot remove it. Aged electronics, cold solder joints, and moisture or corrosion at plugs are also possible.

The control unit may have registered something even though no airbag went off. That is precisely why reading out the fault memory is the sensible starting point.

Voltage spikes, for example from a weak battery or jump-starting, additionally stress the electronics. The crash data only disappears once Airbag24 removes it during repair.

How can you tell that the 77960-TEA-Y420-M4 is defective?

A defect on the 77960-TEA-Y420-M4 shows itself at the airbag warning light in the instrument cluster, at fault messages in the instrument cluster, and at a missing connection to the diagnostic tool. A fault memory that cannot be cleared also belongs to these signs.

• Airbag warning light lights up permanently or intermittently
• Fault message in the instrument cluster
• No connection between diagnostic tool and control unit
• Fault memory cannot be cleared

In an emergency, airbags and seatbelt pretensioners may possibly not deploy. Have the warning checked promptly.

Which vehicles is the 77960-TEA-Y420-M4 fitted in?

The control unit 77960-TEA-Y420-M4 is fitted in these vehicles: Honda Civic 10th generation (2015-2022).

The list below shows the vehicles that Airbag24 has on record for this unit.

• Honda Civic 10th generation (2015-2022)

Comparing the part number on the label of the removed unit with this page only confirms that it is the right unit. The fault memory should be read out beforehand, because only the 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-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-Y420-M4 work?

At Airbag24, checking, repairing and testing the 77960-TEA-Y420-M4 usually take 3–4 working days. Beforehand, have the fault memory read out, disconnect the battery and only then remove the control unit.

Then create a repair order online and send the unit in well packed.

Airbag24 checks the unit on the test bench, replaces defective components, erases the crash data and carries out a function test. Afterwards your own unit goes 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-TEA-Y420-M4 get to Airbag24?

You send the control unit 77960-TEA-Y420-M4 as a parcel, or book a UPS collection for an extra charge. After repair, UPS returns the unit to you.

Include the printed repair order in the parcel and pack the unit shock-resistant.