Airbag control unit with part number 77960-T2A-R020-M4

What does the airbag control unit 77960-T2A-R020-M4 do?

The airbag control unit 77960-T2A-R020-M4 is the control unit of the restraint system (SRS) in Honda vehicles. It checks the signals from the crash sensors, decides within milliseconds whether airbags and seatbelt pretensioners are triggered in an accident, and monitors the system continuously.

After an accident, the unit stores crash data and then locks itself. If faults occur, the airbag warning light in the instrument cluster indicates them.

Why does the control unit 77960-T2A-R020-M4 fail?

The most common cause is crash data that remains in the memory after an accident, even if no airbag has deployed. Other causes come from electronics and connectors.

Crash data cannot be erased with an ordinary diagnostic tool. Airbag24 carries out the erasure during the repair.

• components that age over time
• solder joints that have gone cold
• plug connections where moisture or corrosion acts
• voltage peaks, for example from a weak battery

How can you tell that the 77960-T2A-R020-M4 is defective?

A defect is indicated by the airbag warning light in the instrument cluster, which lights up permanently or intermittently. Typical signs are also fault messages, no connection between the diagnostic tool and the control unit, and a fault memory that cannot be cleared.

• airbag warning light in the instrument cluster, permanently or intermittently
• fault message in the instrument cluster
• diagnostic tool cannot reach the control unit
• fault memory remains and cannot be cleared

In an emergency, airbags and seatbelt pretensioners may then fail to deploy. Please have the fault checked promptly.

Which vehicles is the 77960-T2A-R020-M4 fitted in?

The control unit 77960-T2A-R020-M4 is fitted in these vehicles: Honda Accord 9th generation (2012-2019).

Here is the overview:

• Honda Accord 9th generation (2012-2019)

On the one hand, comparing the part number on the label only serves to identify the correct unit. On the other hand, only a fault memory read out beforehand shows whether the control unit is defective or whether plugs and cables are the cause.

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-R020-M4 work?

Have the fault memory read out first and attach the log before you disconnect the battery and remove the control unit. Then create a repair order online and send in the well-packed unit. At Airbag24, testing, repair and function test usually take 3–4 working days.

Airbag24 tests the unit on the test bench, replaces defective components and erases stored crash data. This is followed by a function test, after which your own unit is returned to you.

The sequence serves safety on the vehicle. 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-R020-M4 get to Airbag24?

You send the control unit 77960-T2A-R020-M4 to Airbag24 as a parcel or book a UPS collection for an extra charge. Your own unit is returned by UPS after the repair.

Put the printed repair order into the parcel and pack the control unit shock-proof.