Airbag control unit with part number 77960-S84-A731-M3

What does the airbag control unit 77960-S84-A731-M3 do?

The airbag control unit 77960-S84-A731-M3 forms the central switching unit of the restraint system (SRS) in Honda. It reads the values from the crash sensors, determines within milliseconds in a crash which airbags and seatbelt pretensioners to trigger, and checks the system for faults constantly. It indicates detected faults via the airbag warning light. After a crash it stores crash data and locks itself.

The monitoring runs in the background throughout the journey. The unit checks wiring, output stages and the connection to the sensors. As soon as something is wrong, it creates a fault entry, so no warning light should be ignored.

Besides the triggering decision, it is therefore also the store for event data that is saved after a crash.

Why does the control unit 77960-S84-A731-M3 fail?

The most common cause is crash data stored in the memory after an accident, even if no airbag has deployed; a normal diagnostic tool cannot remove it. Other possible causes are aged electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes, for example from a weak battery or a jump start.

Crash data can lead to the assumption that the unit is broken. In fact, it only shows that data was stored after an event. A normal readout therefore brings no clarity in this case.

The other causes develop gradually. Components age, solder joints can develop hairline cracks, and moisture attacks the contacts. A stable on-board voltage helps to avoid faults of this kind.

How can you tell that the 77960-S84-A731-M3 is defective?

A defect shows up as the airbag warning light in the instrument cluster, which lights up permanently or intermittently. In addition there is a fault message in the instrument cluster, no connection to the diagnostic tool, and a fault memory that cannot be cleared.

The warning light is the most important indication, because the control unit drives it itself. When it comes on, the unit has stored a fault and is reporting it. If the diagnostic tool then cannot establish a connection, the fault probably lies deeper in the system.

In such a case, airbags and seatbelt pretensioners may possibly not deploy in an emergency. Please have the system checked promptly rather than ignoring the light.

Which vehicles is the 77960-S84-A731-M3 fitted in?

The 77960-S84-A731-M3 is fitted in these vehicles: Honda Accord 6th generation (1998-2002).

The following overview summarises the vehicles in which this control unit has been installed.

• Honda Accord 6th generation (1998-2002)

Before sending in the unit, compare the part number on the label of the removed unit with this page. This only ensures that you are dealing with the right unit. Also have the fault memory read out, because only the log shows whether the control unit itself is defective or whether a plug or a cable is the cause.

For the same vehicles, we also repair control units with the part numbers 77960-S1A-G81-M1, 77960-S1A-G93-M1, 77960-S1A-G94-M1, 77960-S84-A81-M1, 77960-S84-A83-M3, 77960-S84-A84-M1.

How does the repair of the 77960-S84-A731-M3 work?

First have the fault memory read out and enclose the log, then disconnect the battery and only then remove the control unit. Next create a repair order online and send in the unit well packed. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 checks the submitted unit on the test bench and rectifies defective components during the repair. Stored crash data is then erased and a function test is carried out. Afterwards 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-S84-A731-M3 get to Airbag24?

You send the unit as a parcel or arrange a UPS collection for an extra charge. After the repair, Airbag24 returns it by UPS.

Enclose the printed repair order with the unit, and pack the unit so it is shock-resistant.