Airbag control unit with part number P8635A254

What does the airbag control unit P8635A254 do?

The airbag control unit P8635A254 forms the control centre of the restraint system (SRS) for Mitsubishi. It evaluates the crash sensors and decides in an accident which airbags and seatbelt pretensioners fire. After an accident it stores crash data and locks itself.

During operation the unit monitors the entire restraint technology. It checks sensors, firing circuits and connections and passes on deviations.

The lock after an accident is lifted only by the repair. The airbag warning light in the instrument cluster informs you about the state of the system.

Why does the control unit P8635A254 fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed. A normal diagnostic tool cannot remove them. Other causes include ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

That the crash data can be erased means: Airbag24 removes it during the repair. Until then it remains stored.

Electronic components age, and solder joints can give way over time. Moisture and corrosion impair the plug connections, while voltage spikes from a weak battery or a jump start add further strain.

Which cause applies in the individual case is determined only by the examination.

How can you tell that the P8635A254 is defective?

The airbag warning light in the instrument cluster lights permanently or intermittently, a fault message appears in the instrument cluster, the diagnostic tool gets no connection to the control unit, and the fault memory cannot be cleared.

The airbag warning light is the most important sign. It shows that a fault exists in the restraint system. A fault message in the instrument cluster may accompany it.

If the diagnostic tool stays without connection and the fault memory cannot be cleared, the control unit itself may be affected. In an emergency, airbags and seatbelt pretensioners may then fail to trigger. Please have the finding clarified promptly.

Which vehicles is the P8635A254 fitted in?

The control unit P8635A254 is fitted in these vehicles: Mitsubishi Lancer CY (2007-2017).

The following vehicles are known for this part number:

• Mitsubishi Lancer CY (2007-2017)

Check the part number on the label of the removed unit and compare it with this page. This only confirms that you have the right unit. Have the fault memory read out before you remove anything, because it shows whether the control unit is defective or whether a cable is the cause.

For the same vehicles, we also repair control units with the part numbers P8635A146, P8635A168, TARME1308R0924, TARME2937R0152.

How does the repair of the P8635A254 work?

First have the fault memory read out and enclose the log. Then disconnect the battery and remove the control unit. Next, create the repair order online, then pack the unit and send it. At Airbag24, processing usually takes 3–4 working days.

The order ensures that the unit is no longer active before it is removed. Airbag24 tests the control unit on the test bench, replaces defective components, erases stored crash data and carries out a function test. Then your own unit is returned to you.

The time frame refers only to testing, repairing and checking at Airbag24, not to your own working steps. 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 P8635A254 get to Airbag24?

You send the control unit P8635A254 as a parcel to Airbag24 or book a UPS collection. Once the repair is complete, UPS brings the unit back to you.

Enclose the printed repair order and wrap the unit so that it withstands knocks.