Airbag control unit with part number 77960-TMJ-P040-M4

What does the airbag control unit 77960-TMJ-P040-M4 do?

The airbag control unit 77960-TMJ-P040-M4 controls the restraint system (SRS) of Honda. It processes the readings from the crash sensors, determines within fractions of a second in a crash which airbags and seatbelt pretensioners are triggered, and checks the system without interruption. It shows detected faults via the airbag warning light.

In operation, the control runs in the background and decides not only at the moment of impact but in advance, based on the ongoing sensor data. This keeps the restraint system ready at all times.

If an accident occurs, the unit stores crash data and locks itself. The lock is only lifted by the repair.

Why does the control unit 77960-TMJ-P040-M4 fail?

The most common causes are stored crash data from an accident, even if no airbag has triggered, and these cannot be removed with a normal diagnostic tool. Aged electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes, for example from a weak battery or a jump start, are also possible causes.

Crash data remains in the unit after an accident, even if the vehicle continues to drive without damage. Clearing it via diagnosis does not succeed in this case, so the problem persists.

The other causes concern the electronics. Components on the circuit board age, solder joints can go cold, and moisture or corrosion at plug connectors impairs the connection. Voltage spikes, for example from a weak battery or an incorrectly connected jump start, can also disturb the unit.

How can you tell that the 77960-TMJ-P040-M4 is defective?

A defect shows as the airbag warning light in the instrument cluster lit permanently or intermittently, as an error message in the instrument cluster, as a diagnostic tool without connection to the control unit, and as a fault memory that cannot be cleared.

The warning light is the most important sign: it reports that the airbag system has detected a fault. If it lights up, airbags and seatbelt pretensioners may not be able to trigger in an emergency. Have the fault checked promptly rather than ignoring the light. If the diagnostic tool stays without connection to the control unit, or the fault memory cannot be cleared, that is a further sign of a fault in the system.

Which vehicles is the 77960-TMJ-P040-M4 fitted in?

The control unit 77960-TMJ-P040-M4 is fitted in these vehicles: Honda CR-V 5 (2018-2023).

You will find the vehicles for which this control unit is listed in the overview:

• Honda CR-V 5 (2018-2023)

Comparing the part number on the label of the removed unit with this page ensures that you have the matching unit. It does not show the cause. Therefore have the fault memory read out in advance, because the result alone 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-TLA-A240-M4, 77960-TLA-A250-M4, 77960-TLA-A310-M4, 77960-TLA-A320-M4, 77960-TLA-A410-M4, 77960-TLA-A420-M4.

How does the repair of the 77960-TMJ-P040-M4 work?

First have the fault memory read out and enclose the log. Then disconnect the battery and only then remove the control unit. Next create a repair order online and send the unit in well packed.

Airbag24 checks the unit on the test bench and replaces defective components. Stored crash data is deleted, followed by a function test. Processing at Airbag24 usually takes 3–4 working days, after which your own unit is sent 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-TMJ-P040-M4 get to Airbag24?

You send the unit to Airbag24 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 sends it back by UPS. The printed repair order goes into the parcel, and the unit is packed shockproof.

Choose packaging that protects the control unit even during rough transport, and enclose the repair order clearly visible.