Airbag control unit with part number 77960-T0N-M920-M4

What does the airbag control unit 77960-T0N-M920-M4 do?

The airbag control unit 77960-T0N-M920-M4 forms the central control unit of the SRS for Honda. In a crash it analyses the crash sensor signals and decides within milliseconds which airbags and seatbelt pretensioners to trigger.

During operation the unit checks the entire restraint system and shows faults via the airbag warning light in the instrument cluster. This monitoring stays active even when the vehicle is only used briefly.

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

Why does the control unit 77960-T0N-M920-M4 fail?

The most common cause for 77960-T0N-M920-M4 is crash data stored after an accident, even without an airbag deployment; a normal diagnostic tool does not remove it. Other causes are aged electronic components, cold solder joints, moisture and corrosion at plug connectors, as well as voltage spikes.

Airbag24 erases the crash data during the repair. After that the remaining possibilities are examined on the test bench, so the actual cause can be established.

Aged components and cold solder joints belong to the electronics, while moisture and corrosion enter through the plug connectors. Voltage spikes occur when the battery is weakening or when jump-starting is carried out.

How can you tell that the 77960-T0N-M920-M4 is defective?

A defect in the 77960-T0N-M920-M4 shows itself through an airbag warning light that stays on permanently or intermittently, through a fault message in the instrument cluster, through a missing 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 warning light is the sign you should watch for first. It shows the finding directly and does not wait for a later inspection.

• airbag warning light on permanently or intermittently
• fault message in the instrument cluster
• diagnostic tool cannot find the control unit
• fault memory cannot be cleared

Which vehicles is the 77960-T0N-M920-M4 fitted in?

The 77960-T0N-M920-M4 is fitted in these vehicles: Honda CR-V 4 RM (2012-2018).

The vehicles in which this part number occurs are listed here:

• Honda CR-V 4 RM (2012-2018)

Compare the part number on the label of the removed unit with this page. That only confirms that it is the right unit. 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-T0A-3070-M4, 77960-T0A-A012-M1, 77960-T0A-A013-M1, 77960-T0A-A210-M1, 77960-T0A-A212-M1, 77960-T0A-A230-M1.

How does the repair of the 77960-T0N-M920-M4 work?

First have the fault memory read out and enclose the log, then disconnect the battery and 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.

Airbag24 tests the unit on the test bench, replaces defective components, erases crash data and carries out a function test. Afterwards your own unit is returned to you.

The sequence on the vehicle is fixed: the control unit may only be removed once the battery has been disconnected.

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-T0N-M920-M4 get to Airbag24?

Either you send the control unit in as a parcel, or you book a UPS collection for an extra charge. The return after the repair is made by UPS.

Put the printed repair order in the parcel, and pack the unit shock-proof.