Airbag control unit with part number 77960-TAA-J512-M4

What does the airbag control unit 77960-TAA-J512-M4 do?

The airbag control unit 77960-TAA-J512-M4 is the switching centre of the restraint system (SRS) in Honda. It evaluates the signals from the crash sensors, decides in an accident within milliseconds about the triggering of airbags and seatbelt pretensioners, and monitors the system constantly.

If the unit detects a fault, it switches on the airbag warning light in the instrument cluster. In this way it stays visible whether the restraint system is ready for operation.

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

Why does the control unit 77960-TAA-J512-M4 fail?

The most common cause is crash data stored after an accident, even if no airbag has been triggered; a standard diagnostic tool cannot erase it. Other causes are aged electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes, for example from a weak battery or jump-starting.

Crash data remains in the memory until it is deliberately erased. The fact that a diagnostic tool has no access to it is the reason this fault cannot be rectified on its own.

The other causes are of a more general nature. Electronics age, solder joints can go cold, and moisture attacks plug contacts as soon as corrosion forms.

How can you tell that the 77960-TAA-J512-M4 is defective?

Typical signs are an airbag warning light that stays on permanently or intermittently, a fault message in the instrument cluster, a lack of connection to the diagnostic tool, and a fault memory that cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

• Airbag warning light stays on permanently or intermittently
• Fault message in the instrument cluster
• Diagnostic tool cannot establish a connection to the control unit
• Fault memory cannot be cleared

The warning light in the instrument cluster is the clearest of these indications. It shows the fault actively, and you should take this warning seriously.

As soon as one of these signs appears, have the finding clarified.

Which vehicles is the 77960-TAA-J512-M4 fitted in?

The airbag control unit 77960-TAA-J512-M4 is fitted in these vehicles: Honda Stepwgn 5th generation (2015-2022).

The listing shows which vehicles belong to this part number.

• Honda Stepwgn 5th generation (2015-2022)

Compare the part number on the label of the removed unit with this page. This way you can be sure that you have the correct unit. Please have the fault memory read out before removal, because only this log shows whether the control unit is defective or whether a plug or a cable is the cause.

How does the repair of the 77960-TAA-J512-M4 work?

The order is mandatory for safety reasons: have the fault memory read out first and attach the log, then disconnect the battery and only afterwards remove the control unit 77960-TAA-J512-M4. Processing at Airbag24 usually takes 3–4 working days.

Next you create the repair order online and send in the well-packed unit. Airbag24 checks it on the test bench, repairs defective components, erases the stored crash data and carries out a function test.

Afterwards your own unit comes back to you. The stated 3–4 working days apply only to checking, repairing and testing at Airbag24. 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-TAA-J512-M4 get to Airbag24?

You send the control unit 77960-TAA-J512-M4 as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 sends it back to you by UPS.

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