Airbag control unit with part number 77960-SDN-C042-M1

What does the airbag control unit 77960-SDN-C042-M1 do?

The control unit 77960-SDN-C042-M1 is the central control unit of the restraint system (SRS) of Honda. It checks the signals from the crash sensors, decides in a crash within milliseconds whether airbags and seatbelt pretensioners are triggered, and keeps an eye on the system.

The unit reports faults via the airbag warning light in the instrument cluster. The light is therefore the visible part of a monitoring that runs in the background.

After an accident the unit stores crash data and locks itself. This state must be observed during any further measure.

Why does the control unit 77960-SDN-C042-M1 fail?

The most common cause is an entry of crash data from an accident, even if no airbag fired. An ordinary diagnostic tool leaves this entry in place. Other possible causes include ageing electronic components, cold solder joints, moisture, corrosion at plug connections and voltage spikes.

This data sits in the control unit itself. For that reason the fault persists even when plugs and cables are in perfect condition.

The remaining triggers concern the electronics and their surroundings. Ageing, cold solder joints, moisture or corrosion, and voltage spikes, for example from a weak battery or a jump start, can disturb the function.

How can you tell that the 77960-SDN-C042-M1 is defective?

Watch the airbag warning light, which lights up in the instrument cluster permanently or intermittently. In addition a fault message appears, and a diagnostic tool does not find the control unit.

• The light stays on or flickers at irregular intervals
• The instrument cluster shows a message about the airbag system
• The diagnostic tool cannot establish a connection to the control unit
• The fault memory cannot be emptied

In an emergency, airbags and seatbelt pretensioners may then fail to trigger. Such signs should therefore be checked promptly.

Which vehicles is the 77960-SDN-C042-M1 fitted in?

Whether your car matches this unit is shown by comparing the part number. The control unit 77960-SDN-C042-M1 is fitted in these vehicles: Honda Accord 7th generation (2002-2008).

These vehicles are known for this part number:

• Honda Accord 7th generation (2002-2008)

A plug or a cable can also be the cause, so have the fault memory read out before removal. Then compare the part number on the label of the removed unit.

For the same vehicles, we also repair control units with the part numbers 77960-SDA-306, 77960-SDN-C211-M1, 77960-SDR-A021-M4.

How does the repair of the 77960-SDN-C042-M1 work?

First read out the fault memory before removal and enclose the log. Then disconnect the battery, remove the control unit and create a repair order online. Finally, send the well-packed unit to Airbag24.

Airbag24 checks the unit, replaces defective components and deletes the stored crash data. A functional test follows. For checking, repair and testing, 3–4 working days are usually scheduled before your own unit is sent back.

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-SDN-C042-M1 get to Airbag24?

Transport is either by parcel or by a UPS collection that you book for an extra charge. Airbag24 handles the return by UPS.

Pack the control unit shockproof and enclose the printed repair order.