Airbag control unit with part number 77960-TWA-A440-M4

What does the airbag control unit 77960-TWA-A440-M4 do?

The airbag control unit 77960-TWA-A440-M4 is the central control unit of the restraint system (SRS) for Honda. It evaluates the crash sensors and determines in an accident, within milliseconds, which airbags and seatbelt pretensioners are triggered.

In addition, it monitors the system during operation. It shows faults via the airbag warning light in the instrument cluster.

After an accident the control unit stores crash data and locks itself.

Why does the control unit 77960-TWA-A440-M4 fail?

The most common cause is an entry of crash data from an accident, even without a triggered airbag. Other causes include ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Crash data is created as soon as the control unit registers an accident and remains stored afterwards. A standard diagnostic tool cannot erase it. Airbag24 erases it during the repair.

Ageing electronic components and cold solder joints can cause malfunctions. Moisture and corrosion at plug connections also disrupt the contact.

Voltage spikes also affect the unit, for example with a weak battery or jump starting.

How can you tell that the 77960-TWA-A440-M4 is defective?

A defect shows itself through the airbag warning light in the instrument cluster, a fault message, or the diagnostic tool not connecting to the control unit. The fault memory also cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to trigger.

The signs in detail:

• The airbag warning light stays on permanently or intermittently.
• A fault message appears in the instrument cluster.
• The diagnostic tool gets no connection to the control unit.
• The fault memory cannot be cleared.

The warning light is the system's own warning. Anyone who sees it should have the vehicle checked promptly.

Which vehicles is the 77960-TWA-A440-M4 fitted in?

The control unit 77960-TWA-A440-M4 is used in this vehicle: Honda Accord 10th generation (2017-2024).

The assignment at a glance:

• Honda Accord 10th generation (2017-2024)

Compare the part number on the label of the removed unit with this page. That way you can see that it is the right unit. Have the fault memory read out before removal, because only the log 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-T3L-A012-M1, 77960-T3L-C012-M4, 77960-T3L-C020-M4, 77960-T3L-C030-M4, 77960-T3L-F012-M4, 77960-T3L-F020-M4.

How does the repair of the 77960-TWA-A440-M4 work?

First have the fault memory read out and enclose the log, then disconnect the battery and remove the control unit. Then create a repair order online and send in the well-packed unit. Airbag24 checks it on the test bench, replaces defective components, erases stored crash data and carries out a function test.

This sequence is mandatory for safety reasons, so reading out and disconnecting come before removal.

Processing at Airbag24 takes 3–4 working days. 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-TWA-A440-M4 get to Airbag24?

You send the unit as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back to you by UPS.

Place the printed repair order in the parcel and pack the control unit shock-proof.