Airbag control unit with part number 77960-3D4-A820-M1

What does the airbag control unit 77960-3D4-A820-M1 do?

The airbag control unit 77960-3D4-A820-M1 is the central control unit of the restraint system (SRS) for Honda. It evaluates the crash sensors, decides in a crash within milliseconds on airbags and seatbelt pretensioners, and monitors the system continuously.

The unit reports faults via the airbag warning light in the instrument cluster. The evaluation runs in the background throughout the entire journey.

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

Why does the control unit 77960-3D4-A820-M1 fail?

Stored crash data after an accident is the most common cause on the 77960-3D4-A820-M1, even without a triggered airbag, and a normal diagnostic tool does not erase it. Other causes in brief:

• aged electronic components
• cold solder joints
• moisture and corrosion at connectors
• voltage spikes, for example from a weak battery or jump-starting

Crash data is the record of the event in the unit. A read-out shows it, but does not remove it.

The remaining causes concern the electronics. Components age, solder joints can go cold, and moisture or corrosion disturb the signal transmission.

How can you tell that the 77960-3D4-A820-M1 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, and a fault message appears in the instrument cluster. In addition the diagnostic tool cannot connect to the control unit, or the fault memory cannot be cleared.

A defect on the 77960-3D4-A820-M1 thus shows itself in several places at once, and the warning light reports it on its own. A check then clarifies the cause.

As long as the fault persists, airbags and seatbelt pretensioners may possibly not trigger in an emergency. Please have the fault checked promptly.

Which vehicles is the 77960-3D4-A820-M1 fitted in?

The control unit 77960-3D4-A820-M1 is fitted in these vehicles: Honda CR-V 6 (from 2022). The overview shows which vehicles are recorded for this number.

The list is given here.

• Honda CR-V 6 (from 2022)

Matching the part number on the label of the removed unit with this page only clarifies that it is the right unit. Have the fault memory read out beforehand, because only this record shows whether the control unit itself is defective or whether a connector or cable is the cause.

How does the repair of the 77960-3D4-A820-M1 work?

First have the fault memory read out and attach the log. Then disconnect the battery, and only then remove the control unit 77960-3D4-A820-M1. Then create a repair order online and send the unit in well packed.

At Airbag24 the unit is examined on the test bench, defective components are repaired, stored crash data is erased and a function test is carried out. Then your own unit goes back to you.

Processing at Airbag24 usually takes 3–4 working days, meaning checking, repairing and testing at our end. 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 77960-3D4-A820-M1 get to Airbag24?

You send the control unit 77960-3D4-A820-M1 as a parcel or arrange a UPS collection for an extra charge. After the repair Airbag24 returns it to you by UPS.

The printed repair order belongs in the parcel, and the unit must be packed shock-proof.