Airbag control unit with part number 77960-TM8-G820-M2

What does the airbag control unit 77960-TM8-G820-M2 do?

The airbag control unit 77960-TM8-G820-M2 is the control unit of the SRS restraint system of Honda. It monitors the crash sensors, determines in an emergency within milliseconds which airbags and seatbelt pretensioners fire, and tests the system during operation. Faults are shown via the airbag warning light.

In the background it checks voltage, wiring and components continuously. If it detects a fault, it stores the finding in the fault memory.

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

Why does the control unit 77960-TM8-G820-M2 fail?

Most often the failure on the 77960-TM8-G820-M2 is caused by crash data stored after an accident, even without a triggered airbag. A standard diagnostic tool cannot erase them. Other causes are aged components, cold solder joints, moisture and corrosion on plugs, and voltage spikes, for example from a jump start or a weak battery.

Crash data therefore also arise in accidents in which the airbags remained unchanged.

The other causes act over a longer period: electronic components age, and plugs are prone to moisture and corrosion.

How can you tell that the 77960-TM8-G820-M2 is defective?

A defect on the 77960-TM8-G820-M2 shows itself through the airbag warning light, through fault messages, through a lack of connection to the diagnostic tool, or through a fault memory that cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

The signs in detail:

• Warning light in the instrument cluster on permanently
• Warning light on only intermittently
• Message in the instrument cluster
• No connection for the diagnostic tool
• Fault memory remains

If you notice such signs, have the vehicle checked promptly.

Which vehicles is the 77960-TM8-G820-M2 fitted in?

The control unit 77960-TM8-G820-M2 is fitted in these vehicles: Honda Insight 2nd generation (2009-2014). Whether your vehicle is among them can be seen from the details in the vehicle documents.

The vehicles in detail:

• Honda Insight 2nd generation (2009-2014)

You compare the part number on the label of the removed unit with this page. That only ensures that you have the right unit in front of you. Have the fault memory read out beforehand, because only this result shows whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 77960-TM8-A01, 77960-TM8-A020-M2, 77960-TM8-A03.

How does the repair of the 77960-TM8-G820-M2 work?

First have the fault memory of the 77960-TM8-G820-M2 read out and enclose the log; then disconnect the battery and only then remove the control unit. Then create a repair order online and send in the well-packed unit. Processing at Airbag24 usually takes 3–4 working days.

The team at Airbag24 checks the unit on the test bench, replaces defective components, erases the stored crash data and carries out a functional test. Afterwards your own unit comes back to you.

The first steps are fixed for safety reasons. 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-TM8-G820-M2 get to Airbag24?

You send the control unit 77960-TM8-G820-M2 in as a parcel or have it collected by UPS for an extra charge. Airbag24 returns it to you by UPS after the repair.

The printed repair order must go into the parcel, and the unit is to be packed shockproof.