Airbag control unit with part number 77960-SZW-J020-M3

What does the airbag control unit 77960-SZW-J020-M3 do?

The 77960-SZW-J020-M3 controls the restraint system (SRS) of Honda: it processes the readings of the crash sensors, decides in a crash within milliseconds whether airbags and seatbelt pretensioners are deployed, and monitors the entire system.

The control unit detects faults in the system during operation and records them in the fault memory. Via the airbag warning light, it makes them visible to the driver.

After a crash, the unit stores crash data and then locks itself. The lock is only lifted by the repair.

Why does the control unit 77960-SZW-J020-M3 fail?

Control units can fail when their memory holds crash data from an accident, even if no airbag has fired. A normal diagnostic tool cannot delete this data. In addition there are aged electronic components, cold solder joints, moisture and corrosion on plug connections, and voltage spikes from the battery or jump-starting.

Stored crash data can be the trigger of the problem. Because the reading tool does not remove it, the fault persists after the accident, even if the car then drives without any noticeable issues.

The other causes concern the electronics themselves: ageing components, poor solder joints and moisture at the plugs. Which of these applies in the individual case is only established by the test in the workshop.

How can you tell that the 77960-SZW-J020-M3 is defective?

The airbag warning light in the instrument cluster lights up permanently or intermittently, an error message appears in the instrument cluster, the diagnostic tool finds no connection to the control unit, and the fault memory cannot be cleared.

In this state, airbags and seatbelt pretensioners may not trigger in an emergency. This applies regardless of how well the vehicle otherwise runs.

The warning light indicates the defect. You should therefore not ignore the display, but have the fault narrowed down specifically.

Which vehicles is the 77960-SZW-J020-M3 fitted in?

The 77960-SZW-J020-M3 is fitted in these vehicles: Honda Stepwgn 3rd generation (2005-2009).

The assignment is recorded for the following vehicles:

• Honda Stepwgn 3rd generation (2005-2009)

Compare the part number on the label of the removed unit with this page, and you will know that it is the right unit. Also read out the fault memory, because only the result shows whether the control unit is defective or a plug or cable is the cause.

How does the repair of the 77960-SZW-J020-M3 work?

First have the fault memory read out and enclose the log. Then disconnect the battery, remove the control unit and create a repair order online. Afterwards, pack the unit well and send it.

It is essential to follow this order, because the control unit may only be removed after the battery has been disconnected. The log belongs with the unit you send.

Airbag24 checks the unit on the test bench, replaces defective components, deletes the stored crash data and carries out a function test. Processing at Airbag24 generally takes 3–4 working days.

Afterwards you receive your own, repaired unit 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-SZW-J020-M3 get to Airbag24?

Either you send the unit as a parcel, or you book a UPS collection for an extra charge. The return takes place by UPS after the repair.

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