Airbag control unit with part number 77960-TF0-Z421-M3

What does the airbag control unit 77960-TF0-Z421-M3 do?

The airbag control unit 77960-TF0-Z421-M3 is the central component of the restraint system (SRS) for Honda. It collects the signals from the crash sensors and, in an accident, triggers the appropriate airbags and seatbelt pretensioners within milliseconds.

Between accidents the unit monitors the system continuously and reports faults to the airbag warning light.

If an accident has occurred, it stores crash data in memory and is locked afterwards.

Why does the control unit 77960-TF0-Z421-M3 fail?

Stored crash data is the most common cause, and this is the case even if no airbag has deployed. A normal diagnostic tool cannot erase it; during the repair at Airbag24 it is removed.

In addition there are causes that have nothing to do with an accident. Aged components, cold solder joints, moisture and corrosion on plug connections, or voltage spikes, for example from a weak battery, can trigger a failure.

How can you tell that the 77960-TF0-Z421-M3 is defective?

A defect on the 77960-TF0-Z421-M3 may be noticed through the airbag warning light in the instrument cluster. It then stays on permanently or intermittently, and a fault message may appear as well.

Typical signs are:

• fault message in the instrument cluster
• diagnostic tool has no connection to the control unit
• fault memory cannot be cleared

In an emergency, airbags and seatbelt pretensioners may possibly fail to deploy if the control unit is defective.

Which vehicles is the 77960-TF0-Z421-M3 fitted in?

This information applies to Honda. The 77960-TF0-Z421-M3 is fitted in these vehicles: Honda Jazz GE (2008-2015).

The vehicles in detail:

• Honda Jazz GE (2008-2015)

Before you remove the unit, have the fault memory read. That way you can see whether the control unit is really the cause or whether a plug or a cable is affected. Then compare the part number on the label of the removed unit with this information.

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-Z421-M3 work?

Airbag24 usually processes the unit you send in within 3–4 working days, counted only for checking, repairing and testing.

First have the fault memory read and attach the log to the parcel. Then disconnect the battery, remove the control unit, create a repair order online and send it in well packed.

Airbag24 checks the unit on the test bench, replaces defective components, deletes the crash data and carries out a function test. After that, 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-TF0-Z421-M3 get to Airbag24?

The unit is sent in as a parcel, or you book a UPS collection for an extra charge. After the repair, Airbag24 returns it to you by UPS.

Put the printed repair order in the parcel. Pack the control unit securely against shocks.