Airbag control unit with part number MR309212

What does the airbag control unit MR309212 do?

The airbag control unit MR309212 is the central control unit of the restraint system (SRS) in Mitsubishi. It evaluates the crash sensors, determines in a crash which airbags and seatbelt pretensioners trigger, and monitors the system continuously.

The manufacturer number Bosch 0285001232 is also printed on the housing. If the unit detects a fault, the airbag warning light in the instrument cluster displays it.

After a crash, it stores crash data and locks itself.

Why does the control unit MR309212 fail?

Most often it is due to crash data stored after an accident, even if no airbag triggered; they cannot be erased with a normal diagnostic tool. Other causes are aged components, cold solder joints, moisture and corrosion at connectors, and voltage spikes.

Crash data remain the first suspicion, because they directly reflect the consequences that an accident leaves on the unit.

The other causes concern the electronics itself, its connections and the power supply. Electronic components age, solder joints can be cold, moisture attacks connectors, and voltage spikes occur with a weak battery or jump-starting.

Which of these applies is only shown by the fault memory once it has been read out.

How can you tell that the MR309212 is defective?

The airbag warning light in the instrument cluster lights up constantly or intermittently. In addition there are fault messages, a diagnostic tool without connection to the control unit and a fault memory that cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then not trigger.

The warning light is the clearest sign in the vehicle; it reports the defect without you having to search for it.

Whether the control unit or the wiring is affected is only clarified by the diagnosis.

Which vehicles is the MR309212 fitted in?

The MR309212 is fitted in these vehicles: Mitsubishi Carisma DA2A (1999-2002), DA2A (2002-2004) and DA1A (1995-1999).

These vehicles are assigned to the unit with this part number:

• Mitsubishi Carisma DA2A (1999-2002)
• Mitsubishi Carisma DA2A (2002-2004)
• Mitsubishi Carisma DA1A (1995-1999)

Compare the part number on the label of your removed unit with this page. This only establishes that it is the right unit. Also have the fault memory read out in advance; only that result shows whether the control unit is defective or a connector or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 285001127, 285001235, 285001286, 285001290.

How does the repair of the MR309212 work?

First have the fault memory read out and put the log into the parcel, only then disconnect the battery and remove the control unit. Online you create the repair order and send in the well-packed unit. Processing at Airbag24 usually takes 3–4 working days.

Airbag24 checks the unit on the test bench, replaces defective components, erases stored crash data and carries out a functional test. Afterwards you receive your own unit 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 MR309212 get to Airbag24?

You send the control unit as a parcel, or you arrange a UPS collection for an extra charge. Airbag24 sends the repaired unit back to you via UPS.

Pack the unit shock-resistant and include the printed repair order.