Airbag control unit with part number 77960-T2A-D020-M4

What does the airbag control unit 77960-T2A-D020-M4 do?

The airbag control unit 77960-T2A-D020-M4 is the control centre of the restraint system (SRS) in Honda. It processes the readings from the crash sensors, decides within milliseconds in an accident whether airbags and seatbelt pretensioners are triggered, and checks the system continuously.

A detected fault is stored and made visible via the airbag warning light in the instrument cluster. The self-check runs without any action by the driver.

After an accident, the control unit writes crash data and then locks itself.

Why does the control unit 77960-T2A-D020-M4 fail?

The most common cause is crash data from an earlier accident, even if no airbag was triggered; a normal diagnostic tool cannot remove it. Ageing electronics, moisture and voltage spikes are added to this.

Airbag24 removes the crash data during the repair. Independently of this, the following weak points can cause the failure:

• aged electronic components
• cold solder joints
• corrosion and moisture at plug connections
• voltage spikes, for example from a weak battery or a jump start

How can you tell that the 77960-T2A-D020-M4 is defective?

A defect in the 77960-T2A-D020-M4 can be recognised by the airbag warning light, which lights up permanently or intermittently. Error messages in the instrument cluster are added to this. In an emergency, airbags and seatbelt pretensioners may then fail to trigger.

The warning light is the direct signal the vehicle gives you. The fact that it is not lit at a particular moment does not mean the system is fine. A diagnostic tool that cannot connect to the control unit, and a fault memory that cannot be cleared, are further indications of a defect. A display like this is therefore a reason to have the system checked.

Which vehicles is the 77960-T2A-D020-M4 fitted in?

The airbag control unit 77960-T2A-D020-M4 is fitted in these vehicles: Honda Accord 9th generation (2012-2019).

The list of vehicles follows:

• Honda Accord 9th generation (2012-2019)

Compare the part number on the label of the removed unit with this page. This only ensures that it is the correct unit. Whether the control unit itself is defective or a plug or cable is the cause only shows when the fault memory has been read out. Therefore, have it read out before removal.

For the same vehicles, we also repair control units with the part numbers 77960-SEA-G815-M1, 77960-T3L-A012-M1, C0W6K4VDA.

How does the repair of the 77960-T2A-D020-M4 work?

First, have the fault memory read out and enclose the log with the unit. Then disconnect the battery, remove the control unit and create a repair order online. Afterwards, send it in well packed.

The order is binding, because the control unit may only be removed after the battery has been disconnected. Removal therefore belongs at the end of the preparation.

At Airbag24 the unit first goes through a check on the test bench. Afterwards, defective components are processed, stored crash data is deleted and a function test is carried out. Processing usually takes 3–4 working days. Your own unit is then 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-T2A-D020-M4 get to Airbag24?

The control unit 77960-T2A-D020-M4 goes to Airbag24 as a parcel, or you book a UPS collection for an extra charge. After the repair, Airbag24 sends it back by UPS.

Pack the unit shock-resistant, and put the printed repair order into the parcel.