Airbag control unit with part number 8635A317

What does the airbag control unit 8635A317 do?

The airbag control unit 8635A317 manages the restraint system (SRS) of Mitsubishi: it processes the signals from the crash sensors, decides within milliseconds in a crash about airbags and seatbelt pretensioners, and monitors the system continuously. After an accident, it stores crash data and locks itself.

Faults in the restraint system appear on the airbag warning light in the instrument cluster.

A failure of this unit weakens the restraint system.

Why does the control unit 8635A317 fail?

The most common cause for 8635A317 is crash data stored after an accident, even if no airbag has deployed; a normal diagnostic tool cannot erase them. Other causes are aged components, cold solder joints, moisture and voltage spikes.

• aged control electronics
• solder joints that have suffered from temperature changes
• wetness and corrosion in plugs
• voltage spikes on start-up, for example with a weak battery

The crash data show up in the fault memory, which you have read out before removal.

How can you tell that the 8635A317 is defective?

The airbag warning light in the instrument cluster is permanently or intermittently on, and an error message appears in the instrument cluster. The diagnostic tool cannot reach the control unit 8635A317, or the fault memory remains. Airbags and seatbelt pretensioners may then fail to deploy in an emergency.

The cause can lie in the control unit itself, but equally in cables or plugs. Only a diagnosis separates the two.

Which vehicles is the 8635A317 fitted in?

Vehicles with the control unit 8635A317 are: Mitsubishi i-MiEV HA3W (2009-2020).

The list of vehicles follows here:

• Mitsubishi i-MiEV HA3W (2009-2020)

Comparing the label with this page only confirms that the unit is the right one. Have the fault memory read out before removal, because the log shows whether the control unit itself is defective or a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 8635A387.

How does the repair of the 8635A317 work?

For 8635A317, first have the fault memory read out and enclose the log; then disconnect the battery and only afterwards remove the control unit. Then create the repair order online and send the unit in, well packed. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 then examines the unit, repairs the defective components, erases the crash data and tests the function; your unit comes back afterwards.

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 8635A317 get to Airbag24?

You send the control unit 8635A317 as a parcel, or have it collected by UPS for an extra charge. The return after the repair also runs via UPS.

The printed repair order goes into the parcel; pack the unit shockproof.