Airbag control unit with part number 77960-TF0-H420-M3

What does the airbag control unit 77960-TF0-H420-M3 do?

The airbag control unit 77960-TF0-H420-M3 is the link in the restraint system (SRS) of Honda. It evaluates the crash sensors, decides within milliseconds in an accident whether to deploy airbags and seatbelt pretensioners, and monitors the system continuously. After an accident it stores crash data and locks itself.

The control unit receives the messages from the sensors without interruption and records any irregularities in its memory. This keeps the state of the entire system traceable at all times.

The unit reports faults via the airbag warning light in the instrument cluster. The sensors, ignition circuits and display all depend on this unit.

Why does the control unit 77960-TF0-H420-M3 fail?

With the 77960-TF0-H420-M3, the most common cause lies in crash data stored after an accident, even if no airbag has deployed. This data cannot be removed with a normal diagnostic tool. Ageing components, cold solder joints, moisture on connectors and voltage spikes can also cause the failure.

Crash data is not a sign of faulty manufacturing. It arises because the unit records an event that it classifies as an accident.

The unit ages like any other electronics. Over time, components can weaken, solder joints can go cold and moisture or corrosion can form on plug connections.

Voltage spikes are also among the causes, for example when the battery is weak or a jump start has not been connected properly. At Airbag24, the crash data is deleted during the repair.

How can you tell that the 77960-TF0-H420-M3 is defective?

The airbag warning light lights up on the 77960-TF0-H420-M3 permanently or intermittently, and an error message appears in the instrument cluster. The diagnostic tool cannot establish a connection, and the fault memory remains.

Pay particular attention to these signs:

• Airbag warning light that stays on or flashes intermittently
• Error message in the instrument cluster
• Diagnostic tool that cannot establish a connection
• Fault memory that cannot be cleared

If any of these signs is present, airbags and seatbelt pretensioners may not deploy in an emergency. It is therefore worth not waiting.

Which vehicles is the 77960-TF0-H420-M3 fitted in?

The 77960-TF0-H420-M3 is fitted in these vehicles: Honda Jazz GE (2008-2015).

The models with this control unit are listed in the allocation:

• Honda Jazz GE (2008-2015)

Before removal, compare the part number on the label with the information above. Have the fault memory read out beforehand to rule out a cable or plug as the cause of the fault.

For the same vehicles, we also repair control units with the part numbers 5WK43461, 77960-SAA-G821-M1, 77960-SEG-G821-M1, 77960-TF0-G820-M3, 77960-TF0-G821.

How does the repair of the 77960-TF0-H420-M3 work?

Have the fault memory read out before removal and enclose the log. Then disconnect the battery and remove the control unit 77960-TF0-H420-M3. Afterwards, create a repair order online and send the well-packed unit in. Airbag24 checks, repairs and tests it, after which your own unit is returned to you.

At Airbag24, the unit is examined on the test bench. Defective components are replaced, the stored crash data is deleted and a function test is carried out.

For checking, repairing and testing at Airbag24, you can usually expect 3–4 working days. 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-TF0-H420-M3 get to Airbag24?

You send the control unit 77960-TF0-H420-M3 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns it to you by UPS.

Enclose the printed repair order in the parcel. Pack the unit so that it is shock-resistant during transport.