Airbag control unit with part number 77960-SYY-J413-M3

What does the airbag control unit 77960-SYY-J413-M3 do?

The airbag control unit 77960-SYY-J413-M3 forms the central control unit of the SRS restraint system of Honda. It evaluates the signals from the sensors, decides in a collision within milliseconds which airbags and seatbelt pretensioners trigger, and monitors the system continuously. Faults appear via the airbag warning light.

The evaluation runs constantly while driving and distinguishes driving states from an accident.

After an accident the unit stores crash data and locks itself. The workshop therefore begins by reading out the fault memory.

Why does the control unit 77960-SYY-J413-M3 fail?

Stored crash data, which lies in the unit after an accident, is the most common cause, even if no airbag was triggered. A normal diagnostic tool cannot erase it. Further causes are aged electronics, dry solder joints, moisture and corrosion, and voltage spikes.

The other causes at a glance:

• Aged electronic components
• Dry solder joints
• Moisture and corrosion at plug connections
• Voltage spikes (weak battery, jump start)

A diagnosis separates the possibilities: only the fault memory shows which of them applies.

How can you tell that the 77960-SYY-J413-M3 is defective?

A defect shows through the airbag warning light, which stays on permanently or intermittently. Added to this are error messages, a diagnostic tool that cannot make a connection, and a fault memory that cannot be reset. In an emergency, airbags and seatbelt pretensioners may therefore fail to trigger.

The signs appear individually or together, depending on the fault:

• Airbag warning light on permanently or intermittently
• Error message in the instrument cluster
• No connection between the diagnostic tool and the control unit
• Fault memory cannot be cleared

A warning of this kind calls for an inspection.

Which vehicles is the 77960-SYY-J413-M3 fitted in?

The 77960-SYY-J413-M3 is fitted in these vehicles: Honda Freed 1st generation (2008-2016). Comparing the part number on the label only confirms that you have the correct unit.

The list of known vehicles follows here:

• Honda Freed 1st generation (2008-2016)

First compare the part number on the label of the removed unit with this page. Then have the fault memory read out, because only its findings show whether the control unit itself is the cause or a plug or cable.

For the same vehicles, we also repair control units with the part numbers 77960-SFM-J412-M3, 77960-SFM-J420-M3.

How does the repair of the 77960-SYY-J413-M3 work?

First read out the fault memory and enclose the record. Then disconnect the battery and only afterwards remove the control unit. Next create a repair order online and send in the unit securely packed.

Airbag24 checks the 77960-SYY-J413-M3 on the test bench, replaces defective components, clears the stored crash data and carries out a function test. Processing at Airbag24 usually takes 3–4 working days.

After that your own, repaired unit goes back to you.

The order of steps protects you while working on the system, which is why you should follow this sequence.

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-SYY-J413-M3 get to Airbag24?

You either hand in the unit as a parcel, or you book a UPS collection for an extra charge. Airbag24 sends it back to you by UPS after the repair.

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